how to allow only character (a-z) and number(0-9) only in the textbox?

[hidayu1986]

currently i try this code but:

-->for alphanumeric(allow alphanumeric : a-z,0-9,(symbol))
<asp:textbox onkeypress="if(((event.keyCode>=39)&amp;&amp;(even t.keyCode<=39))){event.returnValue=false;}"
id="txtStfNo" runat="server" Font-Names="Arial" Font-Size="9pt" MaxLength="10" Width="440px" Height="60px"></asp:textbox>
 
 
 
<asp:textbox onkeypress="if(((event.keyCode>=39)&amp;&amp;(even t.keyCode<=39))){event.returnValue=false;}"
id="txtccno" runat="server" Font-Names="Arial" Font-Size="9pt" MaxLength="10" Width="440px" Height="60px"></asp:textbox>
 
 
--->allow numeric only
<asp:textbox onkeypress="if(((event.keyCode>=32)&amp;&amp;(even t.keyCode<=47))||((event.keyCode>=58)&amp;&amp;(ev ent.keyCode<=254))){event.returnValue=false;}"
id="Textbox1" runat="server" Font-Names="Arial" Font-Size="9pt" MaxLength="10" Width="152px"></asp:textbox>
 
---allow symbol only
<asp:textbox onkeypress="if(((event.keyCode>=48)&amp;&amp;(even t.keyCode<=57))||((event.keyCode>=65)&amp;&amp;(ev ent.keyCode<=90))||((event.keyCode>=97)&amp;&amp;( event.keyCode<=122)) ){event.returnValue=false;}"
id="Textbox1" runat="server" Font-Names="Arial" Font-Size="9pt" MaxLength="10" Width="152px"></asp:textbox>
 
 

but i want to allow only a-z character and 0-9 number into the textbox. not allow any symbol

[jkmyoung]

event.returnValue=false;
I thought you were supposed to return true, but I could be mistaken.

I suggest writing external functions to make the code cleaner. Then you could have those functions call other functions, like IsDigit(), IsLetter(), IsSymbol(), etc.

Also, you've posted in the wrong forum.