Passing Javascript variable to php

[nbt725]

Dear Sir,

Hello ! I want to get the javascript variable in php code in following function.

[PHP]<script language="JavaScript">
function chg_subcatg(cfield,fieldnm)
{
// For Retrieval of current catg
var f1=document.forms[0];
var sbox1=f1.elements[cfield];
var choice=sbox1.selectedIndex;
var c_catg = sbox1.options[choice].value;
document.forms[0].thefield.value = c_catg;

// For updation of sub category
var f=document.forms[0];
var selectBox=f.elements[fieldnm];
<?php
require_once "../functions_main.inc";
$cxn = Connect_to_db("../vars.inc");
// $sql = "select * from subcatg_mast where catg_id = 1";
$sql = "select * from subcatg_mast where catg_id = " . $t1;

$result = mysql_query($sql);
while ($row = mysql_fetch_array($result))
{
?>
var extraOption=new Option('<?php echo $row['subcatg_desc'];?>','<?php echo $row['catg_id'];?>',0,0);
selectBox.options[selectBox.options.length]=extraOption;

<?php
}
?>

}
[/PHP]

How can I pass the above java script variable c_catg to my %t1 variable to form where clause value in $sql. This variable c_catg has integer value, hence written this way to construct $sql.

Please guide.


Thanks & Regards,

Naimesh Trivedi
[EMAIL REMOVED]-by ajaxrand

[code green]

Javascript is client side and php is server side so you can't directly.
You can put the javascript variable into HTML as a hidden variable or URL variable for example, then submit within a form or via a hyperlink so that PHP can extract it from the POST or GET array.

[ak1dnar]

Javascript is client side and php is server side so you can't directly.
You can put the javascript variable into HTML as a hidden variable or URL variable for example, then submit within a form or via a hyperlink so that PHP can extract it from the POST or GET array.

And also ajaxified solution also suited for this code green.

[code green]

I must confess I keep hearing about Ajax but have never looked into it

[nbt725]

Javascript is client side and php is server side so you can't directly.
You can put the javascript variable into HTML as a hidden variable or URL variable for example, then submit within a form or via a hyperlink so that PHP can extract it from the POST or GET array.

Well if you see the code in the beginning, I do store the variable in a hidden form control. But I don't know how to retrieve it as to my knowledge you need to submit a form either on link or button but not on onClick of a select control.
Can I do so or please let me know any other way to pass that stored variable to my php $sql assignment, which I checked gets displayed, if i change the type from hidden to text.

Thanks & Regards,

Naimesh Trivedi

[ak1dnar]

I must confess I keep hearing about Ajax but have never looked into it

Give It a try buddy. I think this is the Best Tutorial for it.