我是這樣弄的

<script type="text/javascript">
//定義"改變顏色"的函數(shù)
function btn1(){
??? var div=document.getElementById("txt");
??? div.style.color="yellow";
??? div.style.backgroundColor="gray";
}

//定義"改變寬高"的函數(shù)
function btn2(){
??? var div2=document.getElementById("txt");
??? div2.style.width="500px";
??? div2.style.height="300px";
}

//定義"隱藏內(nèi)容"的函數(shù)
function btn3(){
??? var div3=document.getElementById("txt");
??? div3.style.display="none";
}

//定義"顯示內(nèi)容"的函數(shù)
function btn4(){
??? var div4=document.getElementById("txt");
??? div4.style.display="block";
}

//定義"取消設置"的函數(shù)
function btn5(){
??? var div5=document.getElementById("txt");
??? var con=confirm("是否取消設置?");
??? if(con==true){
??????? div5.removeAttribute("style");
??? }
}

? </script>