How can i make it appears in my gui?

[system]

Heres my script :

var ItemIcon : Texture2D;

function OnGUI ()
{  
  GUI.Button(Rect(599,530,60,54),"3"), ItemIcon);
}

How do i make it when GetMouseButtonDown(1) it added in to my gui button?
Like an item added into the GUI.
Will someone help me?

[poncho]

you could use some code like this

var firstpressed: bool = false;

OnGUI…

if(GUI.Button(Rect(599,530,60,54),"3"))
{
    firstpressed = true;
}
if(firstpressed)
{
    GUI.label(rect(599,600,60,54),"The '3' button was pressed");
}