Button to review required fields and then make visible Electronic Signature

I am trying to use the below java script to identify the blank required fields.  If they are complete, I want the electronic signature field visible,  otherwise stay hidden and display the required fields.  My issue is with the signature display part in bold.

if (requiredFields.value == not null) { 

    this.getField("Requestor Electronic Signature").display = display.hidden; 

    app.alert("Error! You must fill in all required Fields:\n"); 

} else { 

     this.getField("Requestor Electronic Signature").display = display.visible; 

} 

var requiredFields = new Array();

for (var i = 0; i < this.numFields; i++)

{

var fName = this.getNthFieldName(i);

var f = this.getField(fName);

if (f.type!="button" && this.getField(fName).required && (this.getField(fName).value == null || this.getField(fName).value == ''))

{

requiredFields[requiredFields.length] = fName;}}

var error = "Please complete the following fields: \n\n";

for (j=0; j < requiredFields.length; j++)

{

if (requiredFields.value == null)

{

error = error + requiredFields + '\n';

var f2 = this.getField(requiredFields);

f2.setFocus();

}

}

if(requiredFields.length > 0)

app.alert(error);

for(var i=0;i<this.numFields;i++)

{

    var cFldName = this.getNthFieldName(i);

    var oFld = this.getField(cFldName);

    if(oFld.required && (oFld.defaultValue == oFld.value))

    {

        app.alert("Field " + cFldName + " is empty");

    }

}