function change(element)
{   
    var open_close=document.getElementById("open_close");
    var imgsrc=open_close.className;

    if(imgsrc.indexOf("icon1")==-1)
    {
    open_close.className="icon1"
    document.getElementById("content1").className="open";
    }
    else
    {
    open_close.className="icon2";
    document.getElementById("content1").className="close";    
    }
}