/* [javascript/Ajax samples 05]
* Summary: common script
* LastModified: 2009-05-04
*/

/*----------------------------------------------------------------------------
search form setup
----------------------------------------------------------------------------*/
function searchForm() {
	var c = {
		msg: "搜尋站內文章",
		errmsg: "請輸入關鍵字",
		classOff: "off"
	}
	
	var form = document.forms["searchform"];
	if(!form) return;
	var field = form.search;
	var btn = document.getElementById("searchsubmit");
	// type="image"無法以form.searchsubmit取得
	
	var msgEle = document.getElementById("message");
	msgEle.appendChild(document.createTextNode(c.errmsg));
	
	if(field.value == "" || field.value == c.msg) {
	// 欄位若為空白則將表單初始化
		field.value = c.msg; 
		field.className = c.classOff;
		btn.className = c.classOff;
		msgEle.style.display = "none";
	}
	
	field.onfocus = function() {
		if(this.value == c.msg) {
		// 欄位若為預設狀態則改為可以輸入並送出的狀態
			this.value = "";
			this.className = "";
			btn.className = "";
		}
		msgEle.style.display = "none";
	};
	field.onblur = function() {
		if(this.value == "") {
		// 欄位若為空白則將表單初始化
			this.value = c.msg;
			this.className = c.classOff;
			btn.className = c.classOff;
		}
		msgEle.style.display = "none";
	};
	btn.onblur = function() {
		msgEle.style.display = "none";
	};
	form.onsubmit = function() {
		// 讓欄位為空白時無法傳送的處理
		if(field.value == "" || field.value == c.msg) {
			msgEle.style.display = "block";
			return false;
		}
		return true;
	};
} // searchForm函數 到此為止

/*----------------------------------------------------------------------------
onload event function
----------------------------------------------------------------------------*/
if(window.addEventListener) {
window.addEventListener("load", searchForm, false);
} else if(window.attachEvent) {
window.attachEvent("onload", searchForm);
}