function ValidDate(emailStr) {

var emailPat   = /^(.+)@(.+)$/;
var userPat    = /^[a-zA-Z0-9\._-]+$/;
var domainPat  = /^[a-zA-Z0-9\.-]+$/;
var invalid0   = /^(.+)\.(.+)\.(.+)$/;
var invalid1   = /^\.(.+)/;
var invalid2   = /(.+)\.$/;
var invalid3   = /\.\./;
var eMailArray = emailStr.match(emailPat);

if (eMailArray == null) {
alert("E-Mail Address is not in a valid format.");
return false;
}

var user      = eMailArray[1];
var dom       = eMailArray[2];

if (user.match(userPat) == null || user.match(invalid0) != null
     || user.length < 3         || user.match(invalid1) != null
                                || user.match(invalid2) != null
                                || user.match(invalid3) != null) {
alert("User Name is not in a valid format.");
return false;
}

if (dom.match(domainPat) == null || dom.indexOf('.') == -1
     || dom.length < 4           || dom.match(invalid1) != null
                                 || dom.match(invalid2) != null
                                 || dom.match(invalid3) != null) {
alert("Domain Name is not in a valid format.");
return false;
}

alert(user.match(invalid_u));
return true;
}