Bug 182673 No default value error message prompts incorrectly
Steps to reproduce: 1. New a report parameter; 2. Choose control type as Combo; 3. Choose parameter as dynamic type; Expected result: As the isRequired is false by default, parameter's default value can be null value. There should be no error message about no default value prompt. Actual result; Error messages prompts
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
return type.equals( DesignChoiceConstants.PARAM_TYPE_DECIMAL );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_FLOAT.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_FLOAT );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_INTEGER.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_INTEGER );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATE.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_DATE );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_TIME.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_TIME );
		}
		return false;
	}
	private String getInputControlType( )
	{
		String type = null;
		if ( inputParameter.getControlType( ) == null )
		{
			type = DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX;
		}
		else if ( DesignChoiceConstants.PARAM_CONTROL_LIST_BOX.equals( inputParameter.getControlType( ) ) )
		{
			if ( inputParameter.isMustMatch( ) )