Enter Only Numbers and Decimal Values Using jQuery

I have used this class only allowed positive numbers and one decimal only

$(document).ready(function() {
     $('input.numbers').keypress(function (event) {
            return isNumber(event, this)
     });
});

// THE SCRIPT THAT CHECKS IF THE KEY PRESSED IS A NUMERIC OR DECIMAL VALUE.
function isNumber(evt, element) {
var charCode = (evt.which) ? evt.which : event.keyCode

if (
      // “-” CHECK MINUS, AND NO MINUS ALLOWED.
       (charCode == 45 || $(element).val().indexOf('-') == -1) &&
      // “-” CHECK MINUS, AND ONLY ONE.
      /*(charCode != 45 || $(element).val().indexOf('-') != -1) && */
      // “.” CHECK DOT, AND ONLY ONE.
      (charCode != 46 || $(element).val().indexOf('.') != -1) &&
      (charCode < 48 || charCode > 57))
      return false;

return true;
}