document.getElementById("terryd").innerHTML = "<img src='terry/screen1.png' class='withshadow' width='500px'/>";
document.getElementById("olgad").innerHTML = "<img src='olga/screen1.png' class='withshadow' width='500px'/>";

function tprev() {
	var img = document.getElementById("tcurrent").value;
	if(img > 1 && img < 8) {
		img--;
		document.getElementById("terryd").innerHTML = "<img src='terry/screen" + img + ".png' class='withshadow' width='500px'/>";
	} else {
	    document.getElementById("terryd").innerHTML = "<img src='terry/screen" + img + ".png' class='withshadow' width='500px'/>";
	}
	document.getElementById("tcurrent").value = img;
}
function tnext() {
	var img = document.getElementById("tcurrent").value;
	if(img < 7) {
		img++;
		document.getElementById("terryd").innerHTML = "<img src='terry/screen" + img + ".png' class='withshadow' width='500px'/>";
	} else {
	    document.getElementById("terryd").innerHTML = "<img src='terry/screen" + img + ".png' class='withshadow' width='500px'/>";
	}
	document.getElementById("tcurrent").value = img;
}

function oprev() {
    var img = document.getElementById("ocurrent").value;
    if (img > 1 && img < 13) {
        img--;
        document.getElementById("olgad").innerHTML = "<img src='olga/screen" + img + ".png' class='withshadow' width='500px'/>";
    } else {
        document.getElementById("olgad").innerHTML = "<img src='olga/screen" + img + ".png' class='withshadow' width='500px'/>";
    }
    document.getElementById("ocurrent").value = img;
}
function onext() {
    var img = document.getElementById("ocurrent").value;
    if (img < 12) {
        img++;
        document.getElementById("olgad").innerHTML = "<img src='olga/screen" + img + ".png' class='withshadow' width='500px'/>";
    } else {
        document.getElementById("olgad").innerHTML = "<img src='olga/screen" + img + ".png' class='withshadow' width='500px'/>";
    }
    document.getElementById("ocurrent").value = img;
}