window.onload = posBottom;

function posBottom(){

    var contentHeight = document.getElementById( 'content' ).offsetHeight;
    var colLeftHeight =  document.getElementById( 'colLeft' ).offsetHeight;
    
    var contentPosY = document.getElementById( 'content' ).offsetTop;
    var colLeftPosY = document.getElementById( 'colLeft' ).offsetTop;
    var bottomPosY = document.getElementById( 'bottom' ).offsetTop;
    
    var diferencaFinal = contentPosY - colLeftPosY;
    diferencaFinal = colLeftHeight - diferencaFinal;
    
    var bottom = document.getElementById( 'bottom' );
    
    if( diferencaFinal > contentHeight ){
        bottom.style.top = ( colLeftHeight + colLeftPosY ) + 'px';
    }else{
        bottom.style.top = ( contentHeight + contentPosY ) + bottom.offsetHeight + 'px';
    }
    
    resizeQuadro();
}