function StripNonDigits(n) {
	if(event.keyCode != 37 && event.keyCode != 39 && event.keyCode != 46){ //Tillåter pil-vänster, pil-höger, delete
		var s = String(n.value);
		var n2 = String();
		for(var i = 0; i < s.length; i++) {
		   var ss = s.substr(i,1);
		   if((ss >= '0' && ss <= '9')||(ss=='-')) { n2 = n2 + ss; }
		   }
		n.value = n2;
	}
}