function swap(button_off, button_on)
{
button_off.src=button_on.src;
}

function ShowPopup1()
{
document.getElementById('tech_popup1').style.display = "block";
}
    
function HidePopup1()
{
document.getElementById('tech_popup1').style.display = "none";
}

function ShowPopup2()
{
document.getElementById('tech_popup2').style.display = "block";
}
    
function HidePopup2()
{
document.getElementById('tech_popup2').style.display = "none";
}