window.onload = function () {resetHeight();};
window.onresize = function () {resetHeight();};

function resetHeight() {
    if (document.getElementById("mainLeft")) {document.getElementById("mainLeft").style.height = "auto";}
    if (document.getElementById("mainRight")) {document.getElementById("mainRight").style.height = "auto";}
    setHeight();
}

function setHeight() {
    var contentHeight;
    if (document.documentElement.clientWidth){
        if (document.getElementById("main")) {contentHeight = document.getElementById("main").clientHeight;}
        //if (document.getElementById("mainIntern")) {contentHeight = document.getElementById("mainIntern").clientHeight;}
    }
    else if (window.innerWidth){
        if (document.getElementById("main")) {contentHeight = document.getElementById("main").innerHeight;}
        //if (document.getElementById("mainIntern")) {contentHeight = document.getElementById("mainIntern").innerHeight;}
    }
    if (document.getElementById("mainLeft")) {document.getElementById("mainLeft").style.height = (contentHeight) + "px";}
    if (document.getElementById("mainRight")) {document.getElementById("mainRight").style.height = (contentHeight) + "px";}
}