ecmascript:

function tracePrint (outputString)
{
	var traceEnabled = false;
	if (traceEnabled) Browser.println ('[trace] ' + outputString);
}

function enabled(value, timeStamp) {

	tracePrint('enabled = ' + value);
	if (value == true)
	{
		if (landed == -1)
		{			
                        status = false;
                        landed = 0;			
		}
                
		if (landed == 0)
		{
			if (status)
			{
				status = false;                               
			}
			else
			{
				status = true;                                			
			}
		}

                else
                {
         		landed = 0;
     			return;
                }
	}
	//print ('status = ' + status);
}