function do_submit()
{
	//checking required fields
	if((document.contact_form.textfield1.value.length == 0) || (document.contact_form.textfield2.value.length == 0) || (document.contact_form.textfield3.value.length == 0) || (document.contact_form.textfield6.value.length == 0) || (getRadioValue() == 0) || (document.contact_form.textarea2.value.length == 0))
	{
		alert ('Please fill in the required (*) fields');
		return false;
	} 
	else
	{
		return verifyEmail(document.contact_form.textfield3.value);
	}
}

function verifyEmail(emailText){
var status = false;     
var emailRegEx = /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i;
     if (emailText.search(emailRegEx) == -1) {
          alert("Please enter a valid email address.");
     }
     else {
          status = true;
     }
     return status;
}

function getRadioValue() {
	var radioValue = 0;
	for (index=0; index < document.contact_form.radiobutton1.length; index++) {
		if (document.contact_form.radiobutton1[index].checked) {
			var radioValue = document.contact_form.radiobutton1[index].value;
			break;
		}
	}
	return radioValue;
}