I make pictures appear but I ddin't figure it out how to make them "disappear"!!!

[Jager]

Hi!! All.....
I tried to make my pic appear by clicking another pic...
Now I have to make it do "disappear" by clicking somthing else after that pic appear . Well, i tried to decrease the index...But it didn't seem to work.....
How should I make it disappear??? :confused:
Oh...One more thing...I am new here and I come from Taiwan.
If anyone blame me about my poor command in English, well,just smile....I will try to work out my English. LOL !!! :thumbsup:

Here is some part of the code.....Thanks a lot...Guys

function showpic (x ,y) {
var o="output"+x;
var oo=eval(o);
oo.innerHTML = '<img src="'+showkeys[y]+'">' ;
This is the code I made my pic appear...but i didn't know how to make it disappear......Obviously, it didn't work out....
unction back(x,y) { x-- ;y-- ;
alert("x="+x+",y="+y);
var o="output"+x;
var oo=eval(o);
oo.innerHTML = '<img src="'+showkeys[y]+'">'
}

[pharma]

dude, just use the <style="visibility: hidden"> tag.

set the picture hidden as default, then on mouse event... replace the hidden with visible. its that easy.