var time_out = 5000;
var time_yanchi =5000;
function jiange_start()
{
window.zixunwang_top.style.visibility="visible";
window.setTimeout( "real_jiange_start()", time_out); 
return false;
}
function real_jiange_start()
{
window.zixunwang_top.style.display="none";
}
function yanchi_jiange_start()
{
window.setTimeout( "jiange_start()", time_yanchi); 
}