/* POPUP */

// Display a popup in a new window
function popup(page, width, height) {
	window.open(page,'popup','width='+width+',height='+height+',left=100,top=100,toolbar=false,scrollbars=1');
}


/* CHECK FORM FUNCTIONS */

// Check userid / email-address
function checkBeforeSend() {

	var user_email = document.getElementById('user_email');
	if(user_email.value != "") {
		// If the mail is valid
		if(isValidEmail(user_email.value)) return true;
	}
	// Alert and put the email field in red
	alert ('Bitte Email-Adresse eintragen');
	user_email.style.border = "1px solid #990000";
	user_email.select();
	user_email.focus();
	return false;
}

// Check if the email is valid
function isValidEmail (email) {
	return /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/.test(email);
}