function IsNumeric(sText) {
  var ValidChars = "0123456789";
  var IsNumber=true;
  var Char;
   
  for (i = 0; i < sText.length && IsNumber == true; i++) { 
    Char = sText.charAt(i); 
    if (ValidChars.indexOf(Char) == -1) {
      IsNumber = false;
    }
	}
	return IsNumber;
}

function overButton(element) {
	element.className="buttonOver";
}
function outButton(element) {
	element.className="buttonOut";
}