function validate_page1(form_name) { 
	var alert_message = "";
	var email_filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9])+$/;

	if (form_name.first_name.value == "") {
		alert_message = "\n - First Name";
	}
	if (form_name.last_name.value == "") {
		alert_message += "\n - Last Name";
	}
	
	if (form_name.email.value == "") {
		alert_message += "\n - Email";
	} else if (!email_filter.test(form_name.email.value)) {
			alertMessage += "\n - E-mail address does not appear valid.";
	} 
		
	if (form_name.current_country.value == "") {
		alert_message += "\n - Country of current residence";
	}
	
	var button_checked = false;
	for (var i=0; i < form_name.re_contact.length; i++) {
		if (form_name.re_contact[i].checked) {
			button_checked = true;
			
		}
	}
	if (button_checked != true) {
		alert_message += "\n - Willing to be re-contacted";
	}
	
	
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}

function validate_page2(form_name) { 
	var alert_message = "";

	if (form_name.age.value == "") {
		alert_message = "\n - Age";
	}
	if (form_name.gender.value == "") {
		alert_message += "\n - Gender";
	}
	
	
	if (form_name.ethnicity.value == "" && form_name.ethnicity_undisclosed.checked != true) {
		alert_message += "\n - Please indicate your ethnicity or check not to disclose ethnic information.";
	}	
	
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}

function validate_page3(form_name) { 
	var alert_message = "";

	var button_checked = false;
	for (var i=0; i < form_name.music_training.length; i++) {
		if (form_name.music_training[i].checked) {
			button_checked = true;
			
		}
	}
	if (button_checked != true) {
		alert_message += "\n - If participants have had musical training, they have to tell ";
		alert_message += "us when it started. Please indicate whether you have had formal ";
		alert_message += "musical training, and, if so, indicate your age when that training began.\n\n";
		alert_message += "Thank you.";	
	}
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}

function validate_page4(form_name) { 
	var alert_message = "";
	var button_checked = false;
	
	for (var i=0; i < form_name.do_you_have_ap.length; i++) {
		if (form_name.do_you_have_ap[i].checked) {
			button_checked = true;
		}
	}
	if (button_checked != true) {
		alert_message += "\n - Please indicate whether you believe you have absolute pitch\n\n";
		alert_message += "Thank you.";
	}
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}

function validate_page5(form_name) { 
	var alert_message = "";
	var button_checked1 = false;
	var button_checked2 = false;
	
	for (var i=0; i < form_name.family_with_ap.length; i++) {
		if (form_name.family_with_ap[i].checked) {
			button_checked1 = true;
		}
	}
	if (button_checked1 != true) {
		alert_message += "\n - Please indicate whether you believe you have any relatives ";
		alert_message += "with absolute pitch and, if so, their relationships to you.\n";
	}

	for (var i=0; i < form_name.multiple_birth_twin.length; i++) {
		if (form_name.multiple_birth_twin[i].checked) {
			button_checked2 = true;
		}
	}
	if (button_checked2 != true) {
		alert_message += "\n - Please indicate whether you are a twin or multiple birth sibling.\n";
	}
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}


function validate_page6(form_name) { 
	var alert_message = "";
	var button_checked = false;
	
	for (var i=0; i < form_name.family_autism.length; i++) {
		if (form_name.family_autism[i].checked) {
			button_checked = true;
		}
	}
	if (button_checked != true) {
		alert_message += "\n - Please indicate whether you believe you have any relatives ";
		alert_message += "with autism spectrum disorders or indicate that you would prefer ";
		alert_message += "not to answer that question\n\n";
		alert_message += "Thank you.";
		
	}
	
	if (alert_message != "") {
		alert("Please complete the required fields marked by \nasterisks(*) before continuing:" + alert_message);
		return false;
	} else {
		return true;
	}
}

function validate_post_comments(form_name) { 

	if (form_name.comments.value == "") {
		alert_message = "\n - Comments";
	}
	
	if (form_name.comments.value == "") {
		alert("- The comment field appears empty.");
		return false;
	} else {
		return true;
	}
}

// validate age was entered
function validate_survey_admin(form_name) { 
	if ( form_name.query_form.table.value == "") {
		alert("Please select which table to query before proceeding");
		return false;
	} else {		
		return true;
	}
}

function definition_popup(url) {
	newwindow=window.open(url,'definition','width=460,height=300,scrollbars,resizable');
	if (window.focus) {
		newwindow.focus()
	}
	return false;
}

function system_sound_test_popup(url) {
	newwindow=window.open(url,'system_sound_test','width=460,height=300,scrollbars,resizable');
	if (window.focus) {
		newwindow.focus()
	}
	return false;
}

function system_requirements_popup(url) {
	newwindow=window.open(url,'system_requirements','width=460,height=400,scrollbars,resizable');
	if (window.focus) {
		newwindow.focus()
	}
	return false;
}

function audio_test_instruction_popup(url) {
	newwindow=window.open(url,'detail','width=460,height=300,scrollbars,resizable');
	if (window.focus) {
		newwindow.focus()
	}
	return false;
}

function skip_ap(form_name) {
	document.form[0].submit();
	return false;
}