function idCheck(form){
	var member_id = form.member_id.value;
	var c;
	for(var i = 0; i < member_id.length; i++){
		c = member_id.substr(i, 1);
		if(!isNumber(c)){
			return false;
		}  
	}
	return true;
}

function itemCheck(form){
	//form.login.disabled = true;
	form.login.style.background = "url(images/email_bg_false.gif) 1px 1px repeat-x";
	if(idCheck(form) && form.member_id.value.length >= 8 && form.password.value != ""){
		//form.login.disabled = false;
		form.login.style.background = "url(images/email_bg.gif) 1px 1px repeat-x";
	}
}

function submitCheck(form){
	if(!(idCheck(form) && form.password.value != "")){
		return false;
	}else{
		form.submit();
	}
}