// 获取宽度
function getWidth()
{
     var strWidth,clientWidth,bodyWidth;
     clientWidth = document.documentElement.clientWidth;
     bodyWidth = document.body.clientWidth;
     if(bodyWidth > clientWidth){
         strWidth = bodyWidth + 20;
     } else {
         strWidth = clientWidth;
     }
     return strWidth;
}
//获取高度
function getHeight()
{
     var strHeight,clientHeight,bodyHeight;
     clientHeight = document.documentElement.clientHeight;
     bodyHeight = document.body.clientHeight;
     if(bodyHeight > clientHeight){
         strHeight = bodyHeight + 30;
     } else {
         strHeight = clientHeight;
     }
     return strHeight;
}
// 锁屏
function showScreen()
{
     var Element = document.getElementById('Message');
     var Elements = document.getElementById('Screen');
     Elements.style.width = getWidth();
     Elements.style.height = getHeight();
     Element.style.display = 'block';
     Elements.style.display = 'block';
}
//解屏
function hideScreen()
{
     var Element = document.getElementById('Message');
     var Elements = document.getElementById('Screen');
     Element.style.display = 'none';
     Elements.style.display = 'none';
}