function hidetext()  

{  

var mychar = document.getElementById("con");

        mychar.style.display = "none";    /*none要用""包含起来*/

}  

function showtext()  

{  

var mychar = document.getElementById("con");

        mychar.style.display = "block";

}

 function hidetext()  

{  

var mychar = document.getElementById("con");

        document.getElementById("con").style.display="none";

}  

function showtext()  

{  

var mychar = document.getElementById("con");

        document.getElementById("con").style.display="block"

}