Percentage Validation

I have a % field on a form and I need to ensure that the user enters a % between 0% and 100%. I tried using the following On User Input scripting, but it does not seem to be working.

if (input.Fee_Percent > 100)
{
alert("Fee Percent cannot be greater than 100%.");
}
if (input.Fee_Percent < 0)
{
alert("Fee Percent cannot be less than 0%.");

Should I just change this field to a drop down filed with only the options for values of 0 to 100 and then change my calculations using this field?