function getMonthDays(month)
{
	if(month==2) return 28;
	else if(month==4 || month==6 || month==9 || month==11) return 30;
	return 31;
}
function insertDays(selectedMonth,id,first_option)
{
	days = getMonthDays(selectedMonth);
			
	document.getElementById(id).length = days + 1;
	document.getElementById(id).options[0].value = 0;
	document.getElementById(id).options[0].text = first_option;
	
	for(i=1; i<=days; i++)
	{
		document.getElementById(id).options[i].value = i;
		document.getElementById(id).options[i].text = i;
	}
}
function isFloat (s)
{  
	var reFloat = /^((\d+(\.\d*)?)|((\d*\.)?\d+))$/
	if (isEmpty(s)) 
	if (isFloat.arguments.length == 1) return defaultEmptyOK;
	else return (isFloat.arguments[1] == true);
	return reFloat.test(s)
}
function isEmpty(s)
{   
	return ((s == null) || (s.length == 0))
}

function isInteger(s)
{   
	var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}
function naviOn(on, offArray)
{
	document.getElementById(on).style.listStyleImage='url(images/orange_arrow.gif)';
	for(i=0; i<offArray.length; i++)
	{
		document.getElementById(offArray[i]).style.listStyleImage='url(images/blue_arrow.gif)';
	}
}