$(document).ready(function(){
	var file_extensions = new Array('jpg','jpeg','png','gif');
	var selector = '';
	var reText = '_off(';
	for( var i = 0; i < file_extensions.length; i++ ){
		selector += ((i!=0) ? ', ' : '') + 'img[src*=_off.' + file_extensions[i] + ']';
		reText   += ((i!=0) ? '|'  : '') + '\.' + file_extensions[i] + '$';
	}
	reText += ')';
	var reOff = new RegExp(reText);
	var reOn  = new RegExp(reText.replace(/_off/, '_on'));
	
	//画像ホバー処理--------------------------------------------------------------//
	$(selector).hover(
		function(){
			var off = $(this).attr('src');
			$(this).attr('src', off.replace(reOff, '_on$1'));
		},function(){
			var on = $(this).attr('src');
			$(this).attr('src', on.replace(reOn, '_off$1'));
		}	
	);
	//----------------------------------------------------------------------------//
	
	//画像プリロード処理----------------------------------------------------------//
	$(selector).each(function(){
		var img = new Image();
		img.src = $(this).attr('src').replace(reOff, '_on$1');
	});
	//----------------------------------------------------------------------------//
});