var emailfilter = /^\w+[\+\.\w-]*@([\w-]+\.)*\w+[\w-]*\.([a-z]{2,4}|\d+)$/i

function checkmail(e) {
    var returnval = emailfilter.test(e.value)
    if (returnval == false) {
        alert("Indtast venligst en gyldig email adresse ")
        e.select()
    }
    return returnval
}