var txt=document.getElementById("txt");

var set={

 function changcolor()

{txt.style.color="blue";

txt.style.backgroundColor="#ccc";},

function changSize()

{txt.style.width="600px";

txt.style.height="400px";},

function objHide()

{txt.style.display="none";},

function objShow()

{txt.style.display= "block";},

function offSet()

{var ans=confirm("是否取消？");

if (ans==true)

   { txt.removeAttribute("style");}

}

}