function changeImageBlog(event)
{   
var tempid = event.id;
var divname = tempid+"_data";
    if(event.value=="close")
    {
        event.src="images/arrow_op.gif";
        event.value="open";
        document.getElementById(divname).style.display = "block"; 
    }
    else
    {
        event.src="images/arrow_cl.gif";
        event.value="close";
        document.getElementById(divname).style.display = "none"; 
    } 
}