var rules = 	{
			'input#fg-deck_officer' : function (element)
			{
				element.onclick = function ()
				{
					if (document.getElementById('fg-deck_officer').checked == true)
					{
						document.getElementById('fg-engineering_officer').disabled = true;
						document.getElementById('fg-electro_technical_officer').disabled = true;
						document.getElementById('fg-engineering_officer').checked = false;
						document.getElementById('fg-electro_technical_officer').checked = false;
					}
					else
					{
						document.getElementById('fg-engineering_officer').disabled = false;
						document.getElementById('fg-electro_technical_officer').disabled = false;
					}
				}
			},
			'input#fg-engineering_officer' : function (element)
			{
				element.onclick = function ()
				{
					if (document.getElementById('fg-engineering_officer').checked == true)
					{
						document.getElementById('fg-deck_officer').disabled = true;
					}
					else
					{
						document.getElementById('fg-deck_officer').disabled = false;
					}
				}
			},
			'input#fg-electro_technical_officer' : function (element)
			{
				element.onclick = function ()
				{
					if (document.getElementById('fg-electro_technical_officer').checked == true)
					{
						document.getElementById('fg-deck_officer').disabled = true;
					}
					else
					{
						document.getElementById('fg-deck_officer').disabled = false;
					}
				}
			}
		}

		Behaviour.register(rules);