鼠标移动到图片上切换到另一张图片，移出时又切回来

<img id="addLineImg" src="pages/annotator/claim/img/plus.png"
onmouseover="this.src='pages/annotator/claim/img/plus2.png';"
onmouseout="this.src='pages/annotator/claim/img/plus.png';"/>

var img=document.createElement("img");
img.setAttribute("src","pages/annottor/claim/img/trash.png");
img.setAttribute("onclick","removeOneWorkitemLine(this);");
img.setAttribute("onmouseover","this.src=\"pages/annottor/claim/img/trash2.png\";");
img.setAttribute("onmouseout","this.src=\"pages/annottor/claim/img/trash.png\";");