var is_netscape = (navigator.appName == 'Netscape') ? true : false;
   
function allowFloatVal(input, event)
{
    var key_code = (is_netscape) ? event.which : event.keyCode;
    if 
        (
            (key_code == 0) ||   // delete, arrows, other...
            (key_code == 8) ||   // backspace
            ((key_code == 46) && (input.value.indexOf('.') < 0)) ||  // dot (only one allowed)
            ((key_code >= 48) && (key_code <= 57)) // numbers 0..9
        )
    {
        return true;
    }   
    if (!is_netscape)
        event.returnValue = false;
    return false;
}
   
function allowIntVal(input, event)
{
    var key_code = (is_netscape) ? event.which : event.keyCode;
    if 
        (
            (key_code == 0) ||   // delete, arrows, other...
            (key_code == 8) ||   // backspace
            ((key_code >= 48) && (key_code <= 57)) // numbers 0..9
        )
    {
        return true;
    }   
    if (!is_netscape)
        event.returnValue = false;
    return false;
}

function doValidateNum(field, error_message)
{
    if (field.value && isNaN(field.value))
    {
        alert(error_message);
        field.focus();
        return false;
    }
    return true;
}

function doRoundNum(number, digits)
{
    var result = Math.round(number * Math.pow(10, digits)) / Math.pow(10, digits);
    result = doPadRight(result, digits); 
    return result;
}

function doPadRight(number, digits)
{
    var result = new String(number);
    var dot_pos = result.indexOf('.');
    if (dot_pos < 0)
    {
        result += '.';
        dot_pos = result.length - 1;
    }
    var count = result.length - dot_pos - 1;
    for (var i = count; i < digits; i++)
        result += '0';
    return result;
}

function doPadLeft(number, digits)
{
    var result = new String(number);
    var count = result.length;
    for (var i = count; i < digits; i++)
        result = '0' + result;
    return result;
}

function isDefined(variable)
{
    return (typeof(variable) != 'undefined');
}

function refreshCaptcha(image_id)
{
    var image_item = document.getElementById(image_id);
    var current_date = new Date();
    image_item.src = 'scripts/verification.php?time=' + current_date.getTime();
}