commentsroll=new Image()
commentsroll.src="../graphix/comments_on.gif"
commentsoff=new Image()
commentsoff.src="../graphix/comments_off.gif"

vartroll=new Image()
vartroll.src="../graphix/vart_on.gif"
vartoff=new Image()
vartoff.src="../graphix/vart_on.gif"

biosroll=new Image()
biosroll.src="../graphix/bios_on.gif"
biosoff=new Image()
biosoff.src="../graphix/bios_off.gif"

poetryroll=new Image()
poetryroll.src="../graphix/poetry_on.gif"
poetryoff=new Image()
poetryoff.src="../graphix/poetry_off.gif"

essaysroll=new Image()
essaysroll.src="../graphix/essays_on.gif"
essaysoff=new Image()
essaysoff.src="../graphix/essays_off.gif"

exhibitsroll=new Image()
exhibitsroll.src="../graphix/exhibits_on.gif"
exhibitsoff=new Image()
exhibitsoff.src="../graphix/exhibits_off.gif"

//new 
var clicked = null

function change_image(whichimage)
{
        if (clicked != whichimage) {
        document.images[whichimage].src = eval(whichimage + "roll.src")
        }
}

function return_image(whichimage)
{
        if (clicked != whichimage){
        document.images[whichimage].src = eval(whichimage + "off.src")
        }
}

function click_image(whichimage){ return true; }