Button to Highlight required fields

I am trying to create a button that highlights all the required fields ,however,the Java script that I have is not working. Can anyone tell me what I am doing wrong?
 
Java Scripts:
 
Create two buttons in a document containing form fields. One button has the JavaScript mouse up action showRequired();
that will highlight all required fields, the other button has the following mouse up action restoreRequired(); that restores the fields to the appearance state they were in before the showRequired() function executed.
 
The script that follows is a document-level JavaScript that defines the functions called by the two buttons.
 
var oFieldNames = new Object(); // used to save the appearance of the fields
function showRequired() {
// Search through all fields for those that are set to required, excluding
// any button fields.
for ( var i=0; i < this.numFields; i++) {
var fname = this.getNthFieldName(i);
var f = this.getField(fname);
if ( (f.type != "button") && f.required) {
// Save appearance data in oFieldNames
oFieldNames[fname]={ strokeColor: f.strokeColor,
fillColor: f.fillColor};
// Assign a red boundary color, and fill color
f.strokeColor=color.red;
f.fillColor=app.runtimeHighlightColor;
}
}
}
// Now restore the fields.
function restoreRequired() {
if ( typeof oFieldNames == "object") {
for ( var o in oFieldNames ) {
var f = this.getField(o);
f.strokeColor=oFieldNames[o].strokeColor;
f.fillColor=oFieldNames[o].fillColor;
}
}
oFieldNames = new Object();
}