//把焦點設置到最後一個可獲取焦點的控件上
//調用實例:  setLastEnableObjectFocus();
function setLastEnableObjectFocus()
{ 
    var formElements = document.forms[0].elements; 
    for(var i=formElements.length; i>0; i--) 
    { 
        var tmpElement = formElements[i]; 
        try 
        { 
            if(tmpElement.type != 'hidden' && tmpElement.readOnly != true && tmpElement.disabled != true && tmpElement.style.display != 'none') 
            { 
                if(tmpElement.readOnly != 'true') 
                { 
                    tmpElement.focus(); 
                    return; 
                } 
                else
                {  
                    continue;
                } 
            } 
        } 
        catch(e)  
        {
            continue; 
        }  
    }