Hi Malik,
Try using this java script,
document.getElementById($parameters.WidgetId).addEventListener("keypress", function(e){
var patternNotOk = eval("/[^0-9]/g");
var text = this.value.replace(patternNotOk, '');
if (this.value != text){
this.value = text;
}
});
And use this on input widget event (OnKeyPress).