function showBG() {

var bg01="picture/b2.jpg"
var bg02="picture/b3.jpg"
var bg03="picture/b4.jpg"
var bg04="picture/b5.jpg"
var bg05="picture/b6.jpg"
var bg06="picture/b7.jpg"
var bg07="picture/a8.jpg"



var x = Math.round(7*Math.random())
if (x == 1) bgvar=bg01
else if (x == 2) bgvar=bg02
else if (x == 3) bgvar=bg03
else if (x == 4) bgvar=bg04
else if (x == 5) bgvar=bg05
else if (x == 6) bgvar=bg06


else bgvar=bg07

document.write("<img src="+bgvar+" width=425 height=150>")
}