var template_directory;
function set_template_directory(dir) {
	template_directory = dir;
}
var tab_clicked;
var displayed_tab = 1;
function tab_clicked(tab) {
	document.getElementById("tab"+displayed_tab+"_content").style.display = "none";
	document.getElementById("tab"+tab+"_content").style.display = "block";
	document.getElementById("tab"+displayed_tab).style.background = "url("+template_directory+"images/black_tab.jpg)";
	document.getElementById("tab"+tab).style.background = "url("+template_directory+"images/red_tab.jpg)";
	displayed_tab = tab;
}
function echeck(str) { // function performs basic validation of an email address
	var email_regex = /^[-a-z0-9~!$%^&*_=+}{\'?]+(\.[-a-z0-9~!$%^&*_=+}{\'?]+)*@([a-z0-9_][-a-z0-9_]*(\.[-a-z0-9_]+)*\.(aero|arpa|biz|com|coop|edu|gov|info|int|mil|museum|name|net|org|pro|travel|mobi|[a-z][a-z])|([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}))(:[0-9]{1,5})?$/i;
    if(email_regex.test(str)){         
		return true   
    }
	return false;
}
function validate_form(form) {
	var errors = new Array();

	if(form.name.value==''  || form.name.value=="Name") {
		errors[1] = 'Please enter your name';
	}
	if( form.email.value==null || form.email.value=="" || form.email.value=="Email" ) {
		errors[2] = 'Please enter your email address';
	}else if(echeck(form.email.value) == false){
		errors[3] = 'Please enter a valid email address';
	}
	if(form.phone.value=='' || form.phone.value=='Phone') {
		errors[4] = 'Please enter your phone number';
	}
	if(form.message.value=='' || form.message.value=='Type your message here') {
		errors[5] = 'Please enter your message';
	}
	var string = '';
	if(errors.length > 0) {
		for(i in errors) {
			if(errors[i].length > 0)
				string += errors[i] + '\n';
		}
		alert(string);
		return false;
	} else {
		return true;
	}
	return false;
}