Bug 165278 this.getDisplayContent()="" in script of text will destroy preview[0801]
Description: this.getDisplayContent()="" in script of text will destroy preview Build number:2.1.2.v20061120 and 2.2.0.v20061117 Steps to reproduce: 1. Insert a text item, select it and switch to script editor 2. Input this.getDisplayContent()="" and preview Expected result: Error message about the incorrect script. Actual result: In 2.1.2, I saw HTTP Status 500 - type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. In 2.2.0, I saw error dialog with java.lang.ClassCastException.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ExecutionContext.java
* get the current page number
	 * 
	 * @return current page number
	 */
	public long getPageNumber( )
	{
		return pageNumber;
	}
	/**
	 * get the total page have been created.
	 * 
	 * @return total page
	 */
	public long getTotalPage( )
	{
		return totalPage;
	}
	/**
	 * is in factory mode
	 * 
	 * @return true, factory mode, false not in factory mode
	 */
	public boolean isInFactory( )
	{
		return true;
	}
	/**
	 * is in presentation mode.
	 * 
	 * @return true, presentation mode, false otherwise