Bug 135465 [smoke]An error occurred when new a casading Parameter
Description: An error occurred when new a casading Parameter Step to reproduce: 1.new a sample db data source and data set 2.New a cascading parameter group, named "gp1", 3.select the data set, then create two cascading parameters, one is row["customernumber"], named p1; the other is row["customername"] Actual result; error message occurred repeatly
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/CascadingParametersDialog.java
{
			choiceSet = DesignEngine.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_STRING_FORMAT_TYPE );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( type ) )
		{
			choiceSet = DesignEngine.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_DATETIME_FORMAT_TYPE );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL.equals( type )
				|| DesignChoiceConstants.PARAM_TYPE_FLOAT.equals( type ) )
		{
			choiceSet = DesignEngine.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_NUMBER_FORMAT_TYPE );
		}
		return choiceSet;
	}
	private String getSelectedDataType( )
	{
		String type = null;
		if ( StringUtil.isBlank( dataTypeChooser.getText( ) ) )
		{
			if ( selectedParameter != null )
			{
				type = selectedParameter.getDataType( );
			}
			else
			{
				type = DesignChoiceConstants.PARAM_TYPE_STRING;
			}