CPackageSelectStructure::WizDisableCopyButton

function WizDisableCopyButton()
			{
				var source = document.getElementById("system-pages");
				if (!source)
					return;

				var items = source.getElementsByTagName("INPUT");

				if (items.length <= 0)
					return;

				var disableCopyButton = true;
				for (var i = 0; i < items.length; i++)
				{
					if (items[i].checked && !items[i].disabled)
					{
						disableCopyButton = false;
						break;
					}
				}

				document.getElementById("move-button-copy").disabled = disableCopyButton;

			}