function firstPage()
{
    document.mainForm.actPage.value = 1;
    document.mainForm.submit();
}

function nextPage()
{
    actPage = Number(document.mainForm.actPage.value) + 1;
    document.mainForm.actPage.value = actPage;
    document.mainForm.submit();
}

function prevPage()
{
    actPage = Number(document.mainForm.actPage.value) - 1;
    document.mainForm.actPage.value = actPage;
    document.mainForm.submit();
}

function lastPage()
{
    document.mainForm.actPage.value = document.mainForm.totPages.value;
    document.mainForm.submit();
}