var to_check_dates = true ;
	
	function check_dates( can_dates_be_the_same_day )
	{
		
		if ( !to_check_dates )
		{
			return true ;
		}

		var form = document.flight_form ;
		if (
				$("#one_way_trip_radio_button").is(':checked')
			)
		{
			return true ;//it's one-way trip: no use of checking it
		}

		var to_dt = jQuery("#to_date").datepicker( 'getDate' ) ;
		var from_dt = jQuery("#from_date").datepicker( 'getDate' ) ;

		if ( !from_dt )
		{
			alert( 'Please select departure date' );
			return false ;
		}
		if ( !to_dt )
		{
			alert( 'Please select arrival date' );
			return false ;
		}
/*
		if ( 
				( from_dt.getTime() >= to_dt.getTime() )
			&& 	( !can_dates_be_the_same_day )
		)
		{
			 alert( 'Please, select right dates.\nThe departure date should be bigger than return-date.' ) ;
			return false ;
		}
		else
*/	   
		if ( 
				( from_dt.getTime() > to_dt.getTime() )
//			&& 	( can_dates_be_the_same_day )
		)
		{
			alert( 'Please, select right dates.\nThe departure date should be bigger or equal than return-date.' ) ;
			return false ;
		}

		
		r = check_passengers_number( form ) ;
		return r ;
		
	}//function check_dates


(function( $ ) {
    // hide date format descriptions
    $('.date_format_desc').hide();


	options = {
	    //appendText: '(yyyy-mm-dd)',
	    //changeMonth: true,
	    maxDate: "+1y",
	    minDate: "+0d",
	    showAnim: '',
	    showOtherMonths: true,
	    selectOtherMonths: true,
	    numberOfMonths: 1

//		,gotoCurrent:true

	    //showOn: 'both', // button|both|focus
	    //buttonImage: 'calendar.gif',
	    //buttonImageOnly: true
	} ;


	  if ( 0 != $("#to_date").length )
	  {
			options.onSelect = function(dateText, inst) { 
				var to_dt = $("#to_date").datepicker( 'getDate' ) ;
				var from_dt = $("#from_date").datepicker( 'getDate' ) ;
				if( 
							( !from_dt )
						|| 	( from_dt.getTime() > to_dt.getTime() ) 
					)
				{
					$( "#from_date" ).datepicker( "option", "defaultDate", dateText ) ;
					$( "#from_date" ).datepicker( "setDate", "" ) ;
				}
			} ;


			$("#to_date").datepicker( options )  ;



			options.onSelect = function(dateText, inst) { 
				var to_dt = $("#to_date").datepicker( 'getDate' ) ;
				var from_dt = $("#from_date").datepicker( 'getDate' ) ;
				if( 
						( !to_dt )
						|| ( from_dt.getTime() > to_dt.getTime() ) 
					)
				{
					$( "#to_date" ).datepicker( "option", "defaultDate", dateText ) ;
					$( "#to_date" ).datepicker( "setDate", "" ) ;
				}
			} ;

			$("#from_date").datepicker( options )  ;

			$("#one_way_trip_radio_button").click( function(){
					$("#to_date").attr( 'disabled', true ) ;

				}
			) ;

			$("#round_trip_radio_button").click( function(){
					$("#to_date").removeAttr( 'disabled' ) ;
				}
			) ;

			if ( $("#one_way_trip_radio_button").is(':checked') )
			{
				$("#to_date").attr( 'disabled', true ) ;
			}
	  }
	  else if ( 0 != $("#date-field" ) )
	  {
			$("#date-field").datepicker( options )  ;
	  }

  })( jQuery ) ;