function checkFields() {
missinginfo = "";

if (document.form.NAME.value == "") {
missinginfo += "\n     -  Name";
}

if (document.form.SURNAME.value == "") {
missinginfo += "\n     -  Surname";
}

if ((document.form.EMAIL.value == "") || 
(document.form.EMAIL.value.indexOf('@') == -1) || 
(document.form.EMAIL.value.indexOf('.') == -1)) {
missinginfo += "\n     -  Email Address";
}

if ((document.form.AREA_CODET.value == "")||
(document.form.TEL.value == "")||
(document.form.AREA_CODET.value.length < 3)||
(document.form.TEL.value.length < 7)) {
missinginfo += "\n     -  Phone";
}

if (document.form.CAR_TYPE.value == "-1") {
missinginfo += "\n     -  Type of Car";
}

if ((document.form.START_DAY.value == "")||
(document.form.START_MONTH.value == "")||
(document.form.START_YEAR.value == "")) {
missinginfo += "\n     -  Starting Date";
}

if ((document.form.END_DAY.value == "")||
(document.form.END_MONTH.value == "")||
(document.form.END_YEAR.value == "")) {
missinginfo += "\n     -  Ending Date";
}

if (missinginfo != "") {
missinginfo ="_____________________________\n" +
"Aşağıdaki belirtilen Girilmesi Zorunlu Alanları Doğru olarak Girmediniz..:\n" +
missinginfo + "\n_____________________________" +
"\nLütfen Bilgileri girin ve formu tekrar gönderin!";
alert(missinginfo);
return false;
return true;
}
else return true;
}