function doCheck(id){
	var objForm=document.getElementById(id);
    if(objForm.userName.value.length==0) {
        objForm.userName.value="游客";
    }
    
    if(objForm.title.value.length==0) {
        alert("请输入标题");
        objForm.title.focus();
        return false;
    }
    
    if(objForm.content.value.length==0) {
        alert("请输入您的评论内容");
        objForm.content.focus();
        return false;
    }
    
    if(objForm.captcha1.value.length==0) {
        alert("请输入验证码");
        objForm.captcha1.focus();
        return false;
    }
    
    objForm.target = "_self";
    return true;
}

function getImage(id) {
	var objForm=document.getElementById(id);
	objForm.captcha.src='image_get.do?cd='+Math.random();
}