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
*/
	public void execute( String script )
	{
		if ( script != null )
		{
			evaluate( script );
		}
	}	
	/**
	 * execute the script. Simply evaluate the script, then drop the return
	 * value
	 * 
	 * @param script
	 *            script statement
	 * @param fileName
	 *            file name
	 * @param lineNo
	 *            line no
	 */
	public void execute( String script, String fileName, int lineNo )
	{
		if ( script != null )
		{
			evaluate( script, fileName, lineNo );
		}
	}
	/**
	 * @return Returns the locale.
	 */
	public Locale getLocale( )