var cnt = 0;

function blankCheck(fld){
	if (fld.value == ""){
		cnt++;
	}
	else {
	}
}

function mailCheck(fld){
	if (fld.value == ""){
		cnt++;
	}
	else if ((fld.value.indexOf("@") == -1)||
	(fld.value.indexOf("@") != fld.value.lastIndexOf("@"))||
	(fld.value.indexOf("@") == fld.value.length -1)||
	(fld.value.indexOf("@") == 0)){
		cnt++;
	}
	else {
	}
}

function checkForm(){
	cnt = 0;
	blankCheck(document.getElementById('name'));
	mailCheck(document.getElementById('mail'));
	blankCheck(document.getElementById('comment'));
	if (cnt > 0){
		alert("Please fill in blanks.");
		return false;
	}
	else {
		return true;
	}
}