//left trim
function ltrim( s ){return s.replace( /^\s*/, "" );}

//right trim
function rtrim( s ){return s.replace( /\s*$/, "" );}

//trim left & right
function trim( s ){return rtrim(ltrim(s));}

//is null or not
function isNull( s ){return (trim(s).length<1);}

function IsEmail(str)
{
	var regexp=/^[\w-]+(\.*[\w-]+)*@([0-9a-z]+(([0-9a-z]*)|([0-9a-z-]*[0-9a-z]))+\.)+[a-z]{2,3}$/i;
	return regexp.test(str);
}

//发送
function checkSend(form) {
	if (trim(form.vc_author.value).length == 0) {
	   alert("姓名 不可为空！");
	   form.vc_author.focus();
		return false;
	}
	
	if (trim(form.vc_email.value).length == 0) {
	   alert("电子邮件 不可为空！");
	   form.vc_email.focus();
		return false;
	}
	
	if(!IsEmail(form.vc_email.value)) {
		alert("提示：电子邮件格式不正确!");
		form.vc_email.focus();
		return false;
	}
	
	var selObj = form.ColumnID;
	if(selObj.options[selObj.selectedIndex].value*1 <=0) {
	   alert("请选择 留言类别！");
		return false;
	}
	
	if (trim(form.vc_title.value).length == 0) {
	   alert("留言主题 不可为空！");
	   form.vc_title.focus();
		return false;
	}
	
	if (trim(form.t_content.value).length == 0) {
	   alert("内容 不可为空！");
	   form.t_content.focus();
		return false;
	}
		
	var codedisplay = document.all.trcode.style.display
	if( form.rand  && codedisplay == ""){
		if (trim(form.rand.value).length == 0) {
		   	alert("请输入 验证码！");
		   	form.rand.focus();
			return false;
		}
	}
	
	return true;
}

/**
* 翻页
*  currentpage 当前页码
*  infoid 信息ID
*  colid 类别ID
*/
function goPage( currentpage ,webid ,columnid)
{
    //columnid=(columnid.length<1)?"0":"columnid";
	var formData = "guestbook.jsp?strWebID="+webid+"&current="+currentpage+"&ColumnID="+columnid;
	location.href = formData;
}

/**
*  上10页
*  currentpage 当前页码
*  infoid 信息ID
*  colid 类别ID
*/
function goPrePage( currentpage ,webid ,columnid)
{
	var page = Math.ceil( currentpage/10 ) ;
	currentpage = (page-1)*10;
	var formData = "guestbook.jsp?strWebID="+webid+"&current="+currentpage+"&ColumnID="+columnid ;
	location.href = formData;
}

/**
*  下10页
*  currentpage 当前页码
*  infoid 信息ID
*  colid 类别ID
*/
function goNextPage( currentpage ,webid ,columnid)
{
	var page =  Math.ceil( currentpage/10 ) ;
	currentpage = (page+1)*10;		
	var formData = "guestbook.jsp?strWebID="+webid+"&current="+currentpage+"&ColumnID="+columnid ;
	location.href = formData;
}

function checkReSend(form) {	
	if (isNull(form.vc_author.value)
		|| isNull(form.vc_email.value)
		|| isNull(form.t_content.value)
		|| isNull(form.rand.value) )
	{
		alert("提示：所有标记（*）的字段都必须填写!");
		return false;
	}
	else if(!IsEmail(form.vc_email.value))
	{
		alert("提示：电子邮件格式不正确!");
		form.vc_email.focus();
		return false;
	}
	else
	{
		return true;
	}
}
/**
 * 重新载入图片验证码
 */
function loadimage() { 
    document.getElementById("randImage").src = "./que_code.jsp?sessionid=guestbook"; 
 }