var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_initializeRequest(InitializeRequest);
prm.add_endRequest(EndRequest);

var btn;

function InitializeRequest(sender, args) 
{
    document.body.style.cursor = "wait";                
    var btnId=args._postBackElement.id;
    btn= document.getElementById(btnId);
    if (btn.type=="button" || btn.type=="submit") 
        btn.disabled=true;
}

function EndRequest(sender, args) 
{                
    document.body.style.cursor = "default";    
    if(btn!=null) btn.disabled=false; 
}

// 用來設定 TextBox 多行時的字數限制
function isMaxLength(txtBox, iMaxLength) {
    if (txtBox) {
        return (txtBox.value.length < iMaxLength);
    }
}