Bug 177439 Need an easy way to determine default value for a dynamic parameter
Currently, I have to bring up the data set editor, preview the results in the data set and make a mental note of the value to use for a report parameter that depends on a data set. It would be nice to have a drop down on the default value field, such as <Select value> which when selected queries the data set and presents me with a list to select from.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
}
				else if ( type.equals( DesignChoiceConstants.PARAM_TYPE_STRING ) )
				{
					previewString = new StringFormatter( isCustom( ) ? formatPattern
							: formatCategroy,
							ULocale.getDefault( ) ).format( Messages.getString( "ParameterDialog.Label.Sample" ) ); 
				}
				else if ( type.equals( DesignChoiceConstants.PARAM_TYPE_INTEGER ) )
				{
					previewString = new NumberFormatter( isCustom( ) ? formatPattern
							: formatCategroy,
							ULocale.getDefault( ) ).format( 1234567890 );
				}
				else
				{
					previewString = new NumberFormatter( isCustom( ) ? formatPattern
							: formatCategroy,
							ULocale.getDefault( ) ).format( 123456789.01234 );
				}
			}
		}
		formatField.setText( displayFormat );
		previewLabel.setText( convertNullString( previewString ) );
		changeFormat.setEnabled( choiceSet != null );
	}
	private String convertNullString( String str )
	{
		if ( str == null )
		{
			return "";