// function parameters are: field - the string field, count - the field for remaining 
 // characters  number and max - the maximum number of characters  
function CountLeft(field, count, max) {
 // if the length of the string in the input field is greater than the max value, trim it 
 if (field.value.length > max) {
 field.value = field.value.substring(0, max);
 } else {
 // calculate the remaining characters  
 count=0
 count.value = max - field.value.length;
 }
}