// email check v 1.0
function mailcheck(email){

var emailcheck = true;
var gotAT = email.indexOf('@');
var gotPOINT = email.lastIndexOf('.');
var gotSPACE = email.indexOf(' ');
var tldLENGTH = email.length;

if (gotAT < 1) emailcheck=false;
if (gotPOINT < gotAT) emailcheck=false;
if (gotSPACE != -1) emailcheck=false;
if (tldLENGTH - gotPOINT <= 2) emailcheck=false;
if (!emailcheck) alert('Please enter a valid e-mail-address!');

return emailcheck;
}