Bug 146796 Error message pop up if display text contain non-digital char when add next item
Description: In decimal type parameter creation,display type is "list box", Error message pop up if "display text" contain non-digital char when add next item. Steps: 1.Create a new decimal parameter 2.Set display type as "list box" 3.Input one item: value:1, display text:test 4.Input another item: Value:2 Actual result: error message pop up: The display text already exists! Expected result: Input item succussfully.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ParameterDialog.java
if ( formatCategroy == null )
				{
					formatCategroy = DesignChoiceConstants.STRING_FORMAT_TYPE_UNFORMATTED;
				}
				formatPattern = inputParameter.getPattern( );
			}
		}
		updateFormatField( );
	}
	private void refreshCheckBoxArea( )
	{
		if ( dirtyProperties.containsKey( CHECKBOX_HIDDEN ) )
		{
			isHidden.setSelection( getProperty( CHECKBOX_HIDDEN ) );
		}
		else
		{
			isHidden.setSelection( inputParameter.isHidden( ) );
		}
		if ( !DesignChoiceConstants.PARAM_CONTROL_CHECK_BOX.equals( getSelectedControlType( ) ) )
		{
			if ( !DesignChoiceConstants.PARAM_CONTROL_TEXT_BOX.equals( getSelectedControlType( ) ) )
			{
				needSort.setEnabled( true );
				if ( dirtyProperties.containsKey( CHECKBOX_SORT ) )
				{
					needSort.setSelection( getProperty( CHECKBOX_SORT ) );
				}
				else
				{