function loadbtn()
{
    var tobj;
    for (i = 1; i <= 6; i++) {
        tobj = document.getElementById('mb'+i);
        tobj.onmouseover = MainMenuOver;
        tobj.onmouseout = MainMenuOut;
    }
}

function MainMenuOver(e)
{
    this.style.backgroundColor = '#707070';
    this.style.color = '#ffffff';
}
function MainMenuOut(e)
{
    this.style.backgroundColor = '#ffffff';
    this.style.color = '#707070'
}