Remove whitespace and replace all chr(13) and chr(10)

Hi all....

I need a script that will, onKeyUp, remove/prevent carriage returns 'chr(13)', line feeds 'chr(10), and multiple spaces in a text area. When a user is typing into the text area and hits Return, it prevents it. If the user presses space multiple times, it only allows a single space.

I have the following from a few scripts I found on EE (I believe part is ZVonko's script) but I don't understand RegExp well enough to edit it to do what I need it to do. It seems to handle the carriage returns well but prevents any spaces from being entered.

<SCRIPT LANGUAGE="JavaScript">
function removeChar(input) {
var output = "";
for (var i = 0; i < input.length; i++) {
if ((input.charCodeAt(i) == 13) && (input.charCodeAt(i + 1) == 10)) {
i++;
output += " ";
} else {
output += input.charAt(i);
   }
}
return output;
}

String.prototype.fullTrim = function()
{
   return this.replace(/\s+/g," ").replace(/^\s*([\s\S]*\S+)\s*$|^\s*$/,"$1");
}
</script>

<form>
<textarea name='txtUserData' rows='8' cols='50' onKeyUp="removeChar(this.form.txtUserData.value);this.value=this.value.fullTrim()"></textarea>
</form>

Thanks in advance,
Chris24