Bug 155766 [Regression]Preview will not refresh the modify in design report
Details: Preview will not refresh the modify in design report Step: 1.New a report design. 2.New a label and input label1. 3.Preview. 4.Switch to Layout and modify the content of label as label2. 5.Preview. Actual result: It preview as "label1" twice. Exception result: Preview "label2" at the second time
viewer/org.eclipse.birt.report.viewer/src/org/eclipse/birt/report/viewer/utilities/WebViewer.java
{
	/**
	 * HTML format name
	 */
	final public static String HTML = "html"; 
	/**