function menu(option){

// return to default state for dom supported browsers

document.getElementById("m1").setAttribute("class", "");
document.getElementById("m2").setAttribute("class", "");
document.getElementById("m3").setAttribute("class", "");
document.getElementById("m4").setAttribute("class", "");
document.getElementById("m5").setAttribute("class", "");

// return to default state for ie6

document.getElementById("m1").setAttribute("className", "");
document.getElementById("m2").setAttribute("className", "");
document.getElementById("m3").setAttribute("className", "");
document.getElementById("m4").setAttribute("className", "");
document.getElementById("m5").setAttribute("className", "");


// change state of selected item

if(option==1){
document.getElementById("m1").setAttribute("class", "selected");
document.getElementById("m1").setAttribute("className", "selected");
}

if(option==2){
document.getElementById("m2").setAttribute("class", "selected");
document.getElementById("m2").setAttribute("className", "selected");
}

if(option==3){
document.getElementById("m3").setAttribute("class", "selected");
document.getElementById("m3").setAttribute("className", "selected");
}

if(option==4){
document.getElementById("m4").setAttribute("class", "selected");
document.getElementById("m4").setAttribute("className", "selected");
}

if(option==5){
document.getElementById("m5").setAttribute("class", "selected");
document.getElementById("m5").setAttribute("className", "selected");
}

}