Bug 120216 Group dialog should be showed even dataset is not set.
- Add a table report item - do not set the data set - try creating a new table group. - An error is shown Expected behavior - As part of the template requirements, we dont want UI to do the validation. User should be able to go and define a group, even if the dataset is not defined.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/util/UIUtil.java
* @param string
	 *            the string to convert
	 * @return the string, or an empty string for null
	 */
	public static String convertToGUIString( String string )
	{
		if ( string == null )
		{
			string = ""; 
		}
		return string;
	}
	/**
	 * Convert the give string to Model style
	 * 
	 * @param string
	 *            the string to convert
	 * @param trim
	 *            specify if the string needs to be trimmed
	 * @return the string, or null for an empty string
	 */
	public static String convertToModelString( String string, boolean trim )
	{
		if ( string == null )
		{
			return null;
		}
		if ( trim )
		{
			string = string.trim( );