Formatting A Percentage Field

Question

I am trying to format a text field to produce a percentage. Currently when I input 50 into the field, it produces 50.00% (rather than 50%).  I am using a javascript that another member recommended, but I would like to know how I can remove the 2 decimal places. 
I am currently using the following document-level JavaScript:
function percentKeystroke() {
    AFNumber_Keystroke(2, 0, 0, 0, "", false);
function percentFormat() {
    event.value = util.printf("%.2f%", event.value);
Along with the following for the custom format and keystroke scripts for the field:
// Custom Format script
percentFormat();
// Custom Keystroke script
percentKeystroke();
Thanks in advance for your help!

Answer 1

I am trying to use the above script to format a field so the end result will be the percent value and the percent symbol. The user needs to be able to enter values of 0%-100%.
If I use the percent option it requires the user enter the value as a decimal other wise 50% enters as 5000% and trying to explain this to my client is useless.
For now the field has no format. so it takes numbers and letters.
I tried the script above but it leaves the field with no formatting, is allowing  letters,  and the user still needs to enter the %.
Any sugguestions.
Thanks