function checkcomform(f) {
    if(document.all || document.getElementByID){
        f.comment.style.background = "white";
    }
    if(f.comment.value.length < 1){
        alert("Въведете коментар.");
        f.comment.focus();
        if(document.all || document.getElementByID){
            f.comment.style.background = "yellow";
        }
    return false;
    }
}