Bug 163636 "controlType" and "mustMatch" should be matched
If "controlType" is combo-box, "mustMatch" should be false; else "controlType" is list-box, "mustMatch" should be true.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
else
		{
			canBeNull = inputParameter.allowNull( );
		}
		return canBeNull;
	}
	private boolean isDefaultChoice( SelectionChoice choice )
	{
		String choiceValue = choice.getValue( );
		String defaultValue = convertToStandardFormat( this.defaultValue );
		if ( canBeNull( ) && choiceValue == null && defaultValue == null )
		{
			return true;
		}
		return choiceValue != null && isEqual( choiceValue, defaultValue );
	}
	private boolean isStatic( )
	{
		return staticRadio.getSelection( );
	}
	private String convertToStandardFormat( String string )
	{
		if ( string != null
				&& DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( getSelectedDataType( ) ) )
		{
			try
			{
				string = convertToStandardFormat( DataTypeUtil.toDate( string,
						ULocale.US ) );
			}