capturing keypresses and checking if alphanumeric

[Noreen Masterson]

hi
i am trying to check each character entered and make sure it is only an alpha-numeric char
function keyCheck(e){
var keyChar = String.fromCharCode(e.which);
//here is where u would have to check the key then
}
document.captureEvents(Event.KEYPRESS);
document.onkeypress = keyCheck;
i know in Java u can use char.isLetterorDigit(myString.charAt(index))
but how can this be done in javascript??
thanx

[Sam Dalton]

This is not really a JSP question, but I would suggest that you look at JavaScript regular expressions, for example:

// create a regular expression to case-
// insensitively match the letters a-z
var varName = new RegExp("[a-z]*", ["g"|"i"|"gi"]);
var matched = varName.test(myString);

where my string is the string to match on (in your case the contents of your field), and matched returns true if the regular expression is matched, and false otherwise.
Nb: The regular expression above is probably not correct, so check a reference such as this for more details.
Hope this helps
Sam

[Noreen Masterson]

sorry if the Q is in the wrong place!!!
anyway- thanx for your help. it was spot on. used the regular expressions in search method
//reg expr /\W/ is a non word
//where a word is made up from [A-Za-z_0-9]
//and /\S\ is non whitespace
if (( keyChar.search(/\W/) != -1) &&(keyChar.search(/\S\) != -1))
alert("char is not alphanumeric or a whitespace")

thanx a million
--Noreen

[Sam Dalton]

Not a problem
Glad to be of assistance.

Sam