var flag=0;
function check(form)
{
    if (flag == 1)
       return false;

if (! form.email.value){
alert("Please Enter An Email Address");
form.email.focus();
form.email.select();
return false;
}

if (! (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,5})+$/.test(form.email.value))){
alert("Invalid E-mail Address")
form.email.focus();
form.email.select();
return false;
}

flag = 1;
return true;
}