function validation()
{
    var submit = true;
    if( document.getElementById('categorySelect').options[document.getElementById('categorySelect').selectedIndex].value == 1 )
    {
        document.getElementById('message01').style.display = 'block';
        submit = false;
    }
    else document.getElementById('message01').style.display = 'none';
    if( document.getElementById('shortText').value == null || document.getElementById('shortText').value == "" )
    {
        document.getElementById('message02').style.display = 'block';
        submit = false;
    }
    else document.getElementById('message02').style.display = 'none';
    if( document.getElementById('advertText').value == null || document.getElementById('advertText').value == "" )
    {
        document.getElementById('message03').style.display = 'block';
        submit = false;
    }
    else document.getElementById('message03').style.display = 'none';
    if( ( document.getElementById('phone').value == null || document.getElementById('phone').value == "") && ( document.getElementById('email').value == null || document.getElementById('email').value == "" ) )
    {
        document.getElementById('message05').style.display = 'block';
        submit = false;
    }
    else document.getElementById('message05').style.display = 'none';

    if( submit ) document.getElementById('adSendForm').submit();
    return false;
}