Javascript to limit input

Need a way to limit what gets entered into an HTML textbox?

Plug this script into your textbox using…

onKeyPress="javascript:return limitinput(event, '0123456789', true);"

Variables

• event – The event that is passed. Just leave is as ‘event’ when you call it.
• strList – Either a black list or white list depending on the next variable.
• bAllow – If false strList acts as a black list. If true strList acts as a white list.

function limitinput(evt, strList, bAllow)
/*Limits the input to strList. If bAllow is true, then
only allow what is in strList. If bAllow is false,
then do not allow what is in strList.
http://blog.nutt.net
*/
{
var charCode = evt.keyCode;
if (charCode==0)
{
charCode = evt.which;
}
var strChar = String.fromCharCode(charCode);
/*controlArray holds the ASCII codes for valid
control commands (BS, CR, LF, etc)*/
var controlArray = Array(0, 8, 9, 10, 13, 27);
var intOut = 0;

if (bAllow==true)
{
if (charCode==8 || charCode==9 || charCode==37 || charCode==39 || charCode==46 || charCode==116 || (strList.indexOf(strChar)!=-1))
/*Valid*/
{
return true;
}
else
{
return false;
}
}
else
{
if (charCode==8 || charCode==9 || charCode==37 || charCode==39 | charCode==46 || charCode==116 || (strList.indexOf(strChar)==-1))
{
return true;
}
else
{
return false;
}
}

}