code: function() {
        
        var v = this.getValue(), str_value = inputEx.IntegerField.superclass.getValue.call(this);
        
        // empty field
        if (v === '') {
           // validate only if not required
           return !this.options.required;
        }
        
        if (isNaN(v)) {
           return false;
        }
        
        return !!str_value.match(/^[\+\-]?[0-9]+$/) && (this.options.negative ? true : v >= 0) && v >= this.options.min && v <= this.options.max;
        
     }
docs: Validate  if is a number