function pop( url )
{
	window.open( url, '', 'height=400,width=600,menubar=no,toolbar=no,status=no,scrollbars=yes,location=no,resizable=no' ) ;
	return ;
}


// validate_magazine_selection
function vms( m )
{
	var f = m.form ;
	
	// get total number of magazines ( n )
	// and allowed number ( r )
	var o = ( m.name.split('_') )[0] ;				
	var n = f.elements[ o + '_choose_n' ].value ;
	var r = f.elements[ o + '_choose_r' ].value ;

	// count checked magazine ( c ) 
	var c = 0 ;
	for ( var i = 1 ; i <= n ; ++i )
	{
		if ( f.elements[ o + '_magazine_' + i ].checked ) {
			++c ;
		}
	}

	// make sure checked magazines ( c ) 
	// is less than that allowed number ( r )
	if ( c > r ) 
	{
		m.checked = false ;
		return false ;
	}

	return true ;
}

var checked_offers = new Array() ;

function checkOffer( f, o )
{
	if ( checked_offers[o] == 1 ) { return true ; } 

	var c = 0 ; var n = 0 ; var r = 0 ;

	for ( var i = 0 ; i < f.elements.length ; ++i )
	{
		if (
			( ! f.elements[ i ].name.indexOf( o + '_magazine_' )  )
			&& ( f.elements[ i ].checked == true )
		)
		{
			// alert( f.elements[ i ].checked ) ;
			c += 1 ;
		}
		else if ( ! f.elements[ i ].name.indexOf( o + '_choose_n' ) ) {
			n = f.elements[ i ].value ;
			// alert( 'n => ' + n ) ;
		}
		else if ( ! f.elements[ i ].name.indexOf( o + '_choose_r' ) ) {
			r = f.elements[ i ].value ;
			// alert( 'r => ' + r ) ;
		}
	}

	if ( c == 0 ) { return true ; }
	
	// mark this offer as checked
//	checked_offers[o] = 1 ;

	if ( c != r )
	{
		var e = document.getElementById( o + '_error' ) ;
		if ( e )
		{
			// e.setAttribute( 'style', 'display: block;' ) ;
			// e.style.display = 'block' ;
		}
		else
		{	
			// alert( 'Please choose ' + r + ' magazines for offer ' + o + '.' ) ;
		}

		var ename = 'offer_error_' + r ;
		e = document.getElementById( ename ) ;
		if ( e )
		{
			e.setAttribute( 'style', 'display: block;' ) ;
			e.style.display = 'block' ;
		}

		ename = 'u_offer_error_' + r ;
		e = document.getElementById( ename ) ;
		if ( e )
		{
			e.setAttribute( 'style', 'display: block;' ) ;
			e.style.display = 'block' ;
		}

		return false ;
	}
	
	// alert( o + ', ' + c + ', ' + r ) ;

	return true ;
}

function uncheckSame( f, i )
{
	var n = i + '_same' ;
	var e = f[n] ;
	if ( e ) { e.checked = false ; }
	return ;
}


function showElementByName( n ) 
{
	var e = document.getElementById( n ) ;
	if ( e ) {
		e.setAttribute( 'style', 'display: block;' ) ;
		e.style.display = 'block' ;
	}
	return ;
}

function hideElementByName( n ) 
{
	var e = document.getElementById( n ) ;
	if ( e ) {
		e.setAttribute( 'style', 'display: none;' ) ;
		e.style.display = 'none' ;
	}
	return ;
}