Why is code freezing and not turning over images consistently?

[tpgames]

Me memory game freezes after I click some cards. I seems to be random as to the number of clicks needed before it freezes.
I posted the entire code, as I am not sure what is needed for help. I am new to Java Script, and trying to learn it as a hobby. I'm stuck! It matters not if cards match or not.

The link to the game is here:
http://www.tpgames.net/gaming/2/memo...yzmemwork.html

Thanks in advance!

<!--
 
var variable = window.name;
if (variable=='')
{
    var num_rows = 4;
    var num_columns = 4;
}
else
{
    var temp1=variable.lastIndexOf("c");
    var num_rows=variable.slice(1,temp1);
    var num_columns=variable.slice(temp1+1,variable.length);
}
 
var num_fields=num_rows * num_columns;
var num_pics=num_rows * num_columns/2;
var opened_pics=0;
var firstclick=0;
var pic1;
var pic2;
var start_time;
var end_time;
var firstimage=0;
var first_clicked_image=0;
var image_number;
var attempts=0;
var allow_click=1;
 
var last_image=25;
 
var covered=new Image;covered.src="/gaming/2/memory/MemoryWORK/q/covered.jpg";
var bild=new Array();
 
bild[0]=new Array(2);
bild[0]["nick"]=new Image;bild[0]["nick"].src="/gaming/2/memory/MemoryWORK/q/101.gif";
bild[0]["avatar"]=new Image;bild[0]["avatar"].src="/gaming/2/memory/MemoryWORK/q/201.gif";
bild[1]=new Array(2);
bild[1]["nick"]=new Image;bild[1]["nick"].src="/gaming/2/memory/MemoryWORK/q/102.gif";
bild[1]["avatar"]=new Image;bild[1]["avatar"].src="/gaming/2/memory/MemoryWORK/q/202.gif";
bild[2]=new Array(2);
bild[2]["nick"]=new Image;bild[2]["nick"].src="/gaming/2/memory/MemoryWORK/q/103.gif";
bild[2]["avatar"]=new Image;bild[2]["avatar"].src="/gaming/2/memory/MemoryWORK/q/203.gif";
bild[3]=new Array(2);
bild[3]["nick"]=new Image;bild[3]["nick"].src="/gaming/2/memory/MemoryWORK/q/104.gif";
bild[3]["avatar"]=new Image;bild[3]["avatar"].src="/gaming/2/memory/MemoryWORK/q/204.gif";
bild[4]=new Array(2);
bild[4]["nick"]=new Image;bild[4]["nick"].src="/gaming/2/memory/MemoryWORK/q/105.gif";
bild[4]["avatar"]=new Image;bild[4]["avatar"].src="/gaming/2/memory/MemoryWORK/q/205.gif";
bild[5]=new Array(2);
bild[5]["nick"]=new Image;bild[5]["nick"].src="/gaming/2/memory/MemoryWORK/q/106.gif";
bild[5]["avatar"]=new Image;bild[5]["avatar"].src="/gaming/2/memory/MemoryWORK/q/206.gif";
 
//EDITED CODE HERE
 
bild[23]["nick"]=new Image;bild[23]["nick"].src="/gaming/2/memory/MemoryWORK/q/124.gif";
bild[23]["avatar"]=new Image;bild[23]["avatar"].src="/gaming/2/memory/MemoryWORK/q/224.gif";
bild[24]=new Array(2);
bild[24]["nick"]=new Image;bild[24]["nick"].src="/gaming/2/memory/MemoryWORK/q/125.gif";
bild[24]["avatar"]=new Image;bild[24]["avatar"].src="/gaming/2/memory/MemoryWORK/q/225.gif";
bild[25]=new Array(2);
bild[25]["nick"]=new Image;bild[25]["nick"].src="/gaming/2/memory/MemoryWORK/q/126.gif";
bild[25]["avatar"]=new Image;bild[25]["avatar"].src="/gaming/2/memory/MemoryWORK/q/226.gif";
 
 
 
 
 
var image_numbers = new Array();
for (var t=0;t < num_fields; t++)
{
    image_numbers[('M'+t)]=new Array();
    image_numbers[('M'+t)]["zahl"]=t;
    image_numbers[('M'+t)]["status"]=0;
}
 
var temp_numbers= new Array();
function init()
{
    for (var t=0;t < num_fields; t++)
    {
        temp_numbers[('M'+t)]=t;
    }
 
    for (var t=0;t < num_fields; t++)
    {   
        do    
        {    
            random_number = Math.round(Math.random() * (num_fields));    
        } while (random_number > (num_fields-1))
        //random_number = (Math.random() * 1000) % num_fields; 
 
        var temp=temp_numbers[('M'+t)];
 
        temp_numbers[('M'+t)]=temp_numbers[('M'+random_number)];
        temp_numbers[('M'+random_number)]=temp;
    }
    for (t=0; t < num_fields; t++) image_numbers[('M'+t)]["zahl"]=temp_numbers[('M'+t)];
}
 
function close(pic1,pic2)
{
    window.document.images[pic1].src=covered.src;
    image_numbers[pic1]["status"]=0;
    window.document.images[pic2].src=covered.src;
    image_numbers[pic2]["status"]=0;
    allow_click=1;
}
 
var game;
var temp;
 
function look(x,y)
{
    if (firstclick==0)
    {
        start_time=new Date();
        firstclick=1;
    }
 
    image_number='M'+(x*num_columns+y);
    if ((firstimage==0) && (image_numbers[image_number]["status"]<3))
    {
        allow_click=0;
        firstimage=1;
 
        pic1=Math.floor(image_numbers[image_number]["zahl"]/2);
 
        if ((image_numbers[image_number]["zahl"] % 2)==0)
            window.document.images[image_number].src=bild[pic1]["avatar"].src
        else
            window.document.images[image_number].src=bild[pic1]["nick"].src;
        image_numbers[image_number]["status"]=10;
        first_clicked_image=image_number;
        allow_click=1;
    }
    else if ((firstimage==1) && (image_numbers[image_number]["status"]<3))
    {
        allow_click=0;
        firstimage=0;
        attempts++;
        pic2=Math.floor(image_numbers[image_number]["zahl"]/2);
        if ((image_numbers[image_number]["zahl"] % 2)==0)
            window.document.images[image_number].src=bild[pic2]["avatar"].src
        else
            window.document.images[image_number].src=bild[pic2]["nick"].src;
        image_numbers[image_number]["status"]=10;
        if (pic1!=pic2)
            window.setTimeout("close(first_clicked_image,image_number)",600);
        else
        {
            opened_pics++;
            allow_click=1;
        }
        if (opened_pics==num_pics) end_time=new Date();
    }
 
    if (opened_pics==num_pics)
    {
        var seconds=Math.floor(eval(((end_time.getTime() - start_time.getTime())) / 1200));
 
        alert("Congratulations, you solved game in "+attempts+" turns and "+seconds+" seconds!")
        if (num_columns == 6)
        {
            if (num_rows == 5)
                document.spiel.Level.value="1";
            else
                document.spiel.Level.value="0";
        }
        else
            document.spiel.Level.value="nix";
        if (document.spiel.Level.value == "0" || document.spiel.Level.value == "1")
            window.document.getElementById('highscore').style.visibility = 'visible';
        document.spiel.Versuche.value=attempts;
        document.spiel.Zeit.value=seconds;
    }
}
 
function loadmemory()
{
    var start=0;
 
    if (document.spiel.settings[0].checked == true) { game="r4c4";start=1; }
    if (document.spiel.settings[1].checked == true) { game="r6c5";start=1; }
    if (document.spiel.settings[2].checked == true) { game="r11c5";start=1; }
 
    window.name=game;
    location.reload();
}
//-->
 

<!--
 
init();
 
 
for (var i=0;i < num_rows; i++)
{
    for (var j=0;j < num_columns; j++)
    {
        document.write('<img src="'+covered.src+'" onClick="if (allow_click==1) look('+i+','+j+')" name="M'+(i*num_columns+j)+'">');
    }
    document.write('<br>');
}
//-->
</script>
 
<table width=100%>
<br>
<tr><td valign="top">Choose your Skill:</td></tr>
<tr><td valign="top">
 
<input type="radio" name="settings" id="s1" value="rookie"> <label for="s1">Rookie</label><br>
 
<input type="radio" name="settings" id="s2" value="advanced"> <label for="s2">Advanced</label><br>
<input type="radio" name="settings" id="s3" value="professional"> <label for="s3">Professional</label>
 
<br><br><br>
 
<input type="button" value="New Game" onClick="loadmemory()">
 
<input type="hidden" name="Level" value="">
<input type="hidden" name="Versuche" value="">
<input type="hidden" name="Zeit" value="0">
 
<input type="submit" id="highscore" style="visibility:hidden" value="Submit Score">
 

[tpgames]

I forgot to add, that I am testing it in professional mode. As, that contains the amount of cards I want to test. It only freezes in professional mode.

[tpgames]

Solved in that I found that the code requires one to have the exact number of images that row x column =. Thus, my 26 images x 2 did not = the 55 images I needed. I only had 52 images.

However, how does one rewrite the code so that it can take any number of images? If this means a complete rewrite of the code, then just say so. I don't want to cause anyone a boat load of work. Thanks!