function trim(str)
{
    return str.replace(/^\s*|\s*$/g,"");
}

function update_day(formname)
{
    var month_element = document.forms[formname].elements['month'];
    var day_element = document.forms[formname].elements['day'];
    var year_element = document.forms[formname].elements['year'];
    
    if (year_element.value > 0 && month_element.value > 0)
	{
	    var days_in_month = new Date(year_element.value, month_element.value, 0).getDate();
	    var selected_day = day_element.options.selectedIndex;

	    if (days_in_month != day_element.length + 1)
		{
		    day_element.length = 1;
		    for (i = 1; i <= days_in_month; i++)
			{
			    day_element.options[i] = new Option(i, i);
			}

		    if (selected_day > days_in_month)
			day_element.options.selectedIndex = days_in_month;    
		    else 
			day_element.options.selectedIndex = selected_day;    
		}
	}

}

function validate_feed_settings(form)
{
    var title = form.elements['title'];
    var description = form.elements['description'];
    
    if (trim(title.value).length == 0)
	{
	    alert("Please enter a title for your feed.");
	    title.focus();
	    return false;
	}
    if (trim(description.value).length == 0)
	{
	    alert("Please enter a description for your feed.");
	    description.focus();
	    return false;
	}
    return true;
}

function validate_cast_settings(form)
{
    var title = form.elements['title'];
    var description = form.elements['description'];
    var month = form.elements['month'];
    var day = form.elements['day'];
    var year = form.elements['year'];
        
    if (trim(title.value).length == 0)
	{
	    alert("Please enter a title for your feed.");
	    title.focus();
	    return false;
	}
    if (trim(description.value).length == 0)
	{
	    alert("Please enter a description for your feed.");
	    description.focus();
	    return false;
	}
    if (( month.value * day.value * year.value == 0) && !(month.value + day.value + year.value == 0))
	{
	    alert("Please enter in a complete date, or click\n\"Do Not Expire\" to set the podcast to never expire.");
	    month.focus();
	    return false;
	}
    return true;
}

function no_expiration(form)
{
    form.month.options.selectedIndex = 0;
    form.day.options.selectedIndex   = 0;
    form.year.options.selectedIndex  = 0;
}


function validate_feedback(form)
{
    var message = form.elements['message'];
    if (trim(message.value).length == 0)
	{
	    alert("Please enter some feedback to send.");
	    message.focus();
	    return false;
	}
    return true;
}