<div class="img_1" id="img_1" >
     <input type="image" class="img_1" src="img/cump.png"></input>
     <div class="noteText" id="noteTxt" type="text" ondblclick ="changeName(this.id);">123</div>
</div>

function changeName(noteTxtId){
        var noteTxt = document.getElementById(noteTxtId);
        noteTxt.style.display= "none";//.style.display= "block"

        var div = noteTxt.parentNode;

        if(!document.getElementById("noteInput")){
            var text=document.createElement("input");
            text.type="text";
            text.id="noteInput";

            text.style.width=getStyle(noteTxt,'width');
            text.style.height=getStyle(noteTxt,'height');
            text.style.marginTop=getStyle(noteTxt,'marginTop');
            text.style.textAlign=getStyle(noteTxt,'textAlign');

            text.value=noteTxt.innerHTML;
            div.appendChild(text);
            text.select();
            text.onblur=function(){
                noteTxt.style.display= "block";
                noteTxt.innerHTML=text.value;
                //text.style.display= "none";
                div.removeChild(text);
        }
        }
     }

     //獲得css文件中的樣式
     function getStyle(obj, attr)
     {
        if(obj.currentStyle)  
        {
        return obj.currentStyle[attr];  //IE
        }else{              
        return getComputedStyle(obj,false)[attr];  //FF
     }
}

.img_1 { 
    width: 80px;
    height:70px;
    position:absolute;   
}

.noteText {
    width:80px;
    height:15px;
    text-align:center;
    margin-top:70px;
    word-break:break-all;
}