function payments_validate_required(field, alerttxt){
    with (field) {
        if (value == null || value == "") {
            alert(alerttxt);
            return false;
        }
        else {
            return true;
        }
    }
}

function payments_validate_integer(field, alerttxt){
    with (field) {
        n = parseFloat(value);
        if (isNaN(n)) {
            alert(alerttxt);
            return false;
        }
        else {
            return true;
        }
    }
}

function payments_validate_nonzero(field, alerttxt){
    with (field) {
        n = parseFloat(value);
        if (n == 0) {
            alert(alerttxt);
            return false;
        }
        else {
            return true;
        }
    }
}

function payments_validate_form(thisform){
    with (thisform) {
        if (payments_validate_required(company, PAYMENTS_ERROR_1) == false) {
            company.focus();
            return false;
        }
        if (payments_validate_required(description, PAYMENTS_ERROR_1) == false) {
            description.focus();
            return false;
        }
        if (payments_validate_integer(amount1, PAYMENTS_ERROR_2) == false) {
            amount1.focus();
            return false;
        }
        if (payments_validate_nonzero(amount1, PAYMENTS_ERROR_2) == false) {
            amount1.focus();
            return false;
        }
        if (payments_validate_integer(amount2, PAYMENTS_ERROR_2) == false) {
            amount2.focus();
            return false;
        }
    }
}