allow only numbers in textbox c3 mvc code example

Example: allow only numbers in textbox with core 3.0 mvc asp-for

function ValidateNumber(e) {
           var evt = (e) ? e : window.event;
           var charCode = (evt.keyCode) ? evt.keyCode : evt.which;
           if (charCode > 31 && (charCode < 48 || charCode > 57)) {
               return false;
           }
           return true;
       };