function trim(str, chars) {   
    return ltrim(rtrim(str, chars), chars);   
}   
  
function ltrim(str, chars) {   
    chars = chars || "\\s";   
    return str.replace(new RegExp("^[" + chars + "]+", "g"), "");   
}   
  
function rtrim(str, chars) {   
    chars = chars || "\\s";   
    return str.replace(new RegExp("[" + chars + "]+$", "g"), "");   
}  

function search_check() {
	if (trim(document.frm.search_key.value)=="") {
		alert("請輸入搜尋關鍵字!");
		document.frm.search_key.focus();
		return false;
	}
}