Keydown with number value only

Keydown with number value only not enter alphabat

by Ankit Patidar

HTML

Only numbers please: 
<input type="text" name="someid" class="quantityinput" />

JavaScript

$(".quantityinput").keydown(function(evt){
    var charCode = (evt.which) ? evt.which : event.keyCode
    if (charCode > 31 && (charCode < 48 || charCode > 57 && charCode < 96 || charCode > 105))//96 to 105 user for numpad
        
        //if (charCode > 31 && (charCode < 37 || charCode > 40 && charCode < 46 || charCode > 57 && charCode < 96 || charCode > 105))//31 to 37 for left right && 96 to 105 user for numpad
        return false;
        return true;
});