فکر کنم این بدرتون بخوره
فایل را پیوست کردم
if (formArea.email.value.length >0 && (formArea.email.value.indexOf("@",0) == -1||formArea.email.value.indexOf(".",0) == -1)) {
errorMsg +="\n\tEmail\t\t- Enter your valid email address";
errorMsgLong += "\n- If you don't want to enter your email address then leave the email field blank";
}