var ar = new Array("<IMG SRC=html/andrew_03.gif width=827 height=423 border=0>", 
"<IMG SRC=html/george_03.gif width=830 height=425 border=0>",
"<IMG SRC=html/margaret_03.gif width=830 height=425 border=0>",
"<IMG SRC=html/mike_03.gif width=830 height=425 border=0>"); 
var num = Math.floor(Math.random() * ar.length);
document.write(ar[num]);