<!--
function iszahl(cur)
{
	var checkString = cur.value;
	var fehler = false;
	var count = 0;         // COUNTER FOR LOOPING THROUGH STRING
	var checkLen = checkString.length

	var msg = " Das Feld darf nur Zahlen enthalten !"; 	

    	for (count = 0; count < checkLen; count++) 
	{
		ch = checkString.charAt(count);
		if (!(((ch >= "0") && (ch <= "9")) || (ch == ".") || (ch == ",") || (ch == "-") || (ch == "+")))
		{
			fehler = true;
			break;
		}
	}	
	if( fehler)
	{
		alert(msg);
		cur.value=""
		cur.focus();
	}
	return fehler;
}
// -->