How to pull up textfield as email subject line when submitting PDF form.

I have made a form where I get customers to fill up the form in iPad. When they fill up the form and hit submit. I need some of the filled up information as subject line of email. Such as, Name field & Phone number. 

I have added Javascript but ipad version or mobile version gives an error that javascript cannot run.

Here's the online form if required: Courtesy Car Form or Insurance Quotation Form 

var customSubject1 = this.getField("Driver's Name").value;
var customSubject2 = this.getField("Contact Number").value; 
var customSubject3 = this.getField("Driver's license Number").value;
var str1 = " Courtesy Car Form = ";
var str2 = " | ";
var mailtoUrl = "mailto:atmiyaautocare@gmail.com?subject=" + str1 + customSubject1 + str2 + customSubject2 + str2 + customSubject3;
this.submitForm({
 cURL: mailtoUrl, bPDF:true
});