function tabclick(div) {
    tabs = document.getElementsByClassName('tab');
    if (tabs[div] == tabs[0]) {
        tabs[0].style.backgroundImage = "url(images/"+tabs[0].id+"current.png)";
        tabs[1].style.backgroundImage = "url(images/"+tabs[1].id+".png)";
    } else {
        tabs[1].style.backgroundImage = "url(images/"+tabs[1].id+"current.png)";
        tabs[0].style.backgroundImage = "url(images/"+tabs[0].id+".png)";
    }
}
function overtab(div){
    tabs = document.getElementsByClassName('tab');
    if (tabs[div] == tabs[0]) {
        if (tabs[0].style.backgroundImage == 'url("images/'+tabs[0].id+'current.png")'){
            ;
        } else{
            tabs[0].style.backgroundImage = 'url("images/'+tabs[0].id+'roll.png")';
        }
        tabs[1].style.backgroundImage = "url(images/"+tabs[1].id+".png)";
    } else {
        if (tabs[1].style.backgroundImage == 'url("images/'+tabs[1].id+'current.png")'){
            ;
        } else{
            tabs[1].style.backgroundImage = 'url("images/'+tabs[1].id+'roll.png")';
        }
        tabs[0].style.backgroundImage = 'url("images/'+tabs[0].id+'.png")';
    }
}
function offtab(div){
    tabs = document.getElementsByClassName('tab');
    if (tabs[div] == tabs[0]) {
        if (tabs[0].style.backgroundImage == 'url("images/'+tabs[0].id+'current.png")'){
            ;
        } else{
            tabs[0].style.backgroundImage = 'url("images/'+tabs[0].id+'.png")';
            tabs[1].style.backgroundImage = 'url("images/'+tabs[1].id+'current.png")';
        }
    } else {
        if (tabs[1].style.backgroundImage == 'url("images/'+tabs[1].id+'current.png")'){
            ;
        } else{
            tabs[1].style.backgroundImage = 'url("images/'+tabs[1].id+'.png")';
            tabs[0].style.backgroundImage = 'url("images/'+tabs[0].id+'current.png")';
        }
    }
}