Bug 153523 OK button in parameter dialog is enabled without default value in combo-box
Description: OK button in parameter dialog is enabled without default value in combo-box Steps to reproduce: 1. New a report parameter, combo-box. 2. Click New button, input abc as value, click OK 3. Set abc as default value and close Edit Parameter dialog. 4. New a data source and dataset 5. Edit the parameter, remove abc value and import values from dataset Expected result: OK button is disabled for there is no default value. Actual result: OK button is enabled.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
{
		
		if ( ( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX.equals( getSelectedControlType( ) ) || PARAM_CONTROL_LIST.equals( getSelectedControlType( ) ) )
				&& DesignChoiceConstants.PARAM_TYPE_STRING.equals( getSelectedDataType( ) ) )
		{
			allowBlank.setEnabled( true );
		}
		else
		{
			allowBlank.setEnabled( false );
		}
		
		if ( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX.equals( getSelectedControlType( ) ) )
		{
			doNotEcho.setEnabled( true );
		}
		else
		{
			doNotEcho.setEnabled( false );
		}
		
		if ( DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX.equals( getSelectedControlType( ) )
				|| DesignChoiceConstants.PARAM_CONTROL_CHECK_BOX.equals( getSelectedControlType( ) ) )
		{
			needSort.setEnabled( false );
		}
		else
		{
			needSort.setEnabled( true );
		}