 20, 20, 300, 240,
						'overflow=fill;fillColor=none;fontColor=#000000;');
					var v2 = graph.insertVertex(parent, null, 'Hello,', 480, 320, 300, 240,
						'overflow=fill;fillColor=none;fontColor=#000000;');
					var e1 = graph.insertEdge(parent, null, '', v1, v2);
				}
				finally
				{
					// Updates the display
					graph.getModel().endUpdate();
				}
				
				document.body.appendChild(mxUtils.button('+', function()
				{
					graph.zoomIn();
				}));
				document.body.appendChild(mxUtils.button('-