Try this
var intRegex = /^(?:[1-9]\d*(?:\.\d\d?)?|0\.[1-9]\d?|0\.0[1-9])$/;
In Client Side use JavaScript Code
$('#YourField').change(function () {
var v = parseFloat(this.value);
if (isNaN(v)) {
this.value = '';
} else {
this.value = v.toFixed(2);
}
});