function reference(url) 
{
window.open(url,'reference',"height=400, width=700,resizable,scrollbars=yes,top=25, left,25")
}
function image(url) 
{
window.open(url,'reference',"height=440, width=560,resizable,scrollbars=yes,top=25, left,25")
}

function newwindow(url) 
{
window.open(url,'reference',"height=480, width=740,resizable,scrollbars=yes,top=25, left,25")
}