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 ( choiceSet == null )
		{
			formatCategroy = formatPattern = null;
		}
		else
		{
			if ( !loading
					|| ( ( inputParameter.getCategory( ) == null && inputParameter.getPattern( ) == null ) ) )
			{
				if ( DesignChoiceConstants.PARAM_TYPE_STRING.equals( getSelectedDataType( ) ) )
				{
					formatCategroy = choiceSet.findChoice( DesignChoiceConstants.STRING_FORMAT_TYPE_UNFORMATTED )
							.getName( );
				}
				else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( getSelectedDataType( ) ) )
				{
					formatCategroy = choiceSet.findChoice( DesignChoiceConstants.DATETIEM_FORMAT_TYPE_UNFORMATTED )
							.getName( );
				}
				else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL.equals( getSelectedDataType( ) )
						|| DesignChoiceConstants.PARAM_TYPE_FLOAT.equals( getSelectedDataType( ) ) )
				{
					formatCategroy = choiceSet.findChoice( DesignChoiceConstants.NUMBER_FORMAT_TYPE_UNFORMATTED )
							.getName( );
				}
				formatPattern = null;
			}
			else
			{
				formatCategroy = inputParameter.getCategory( );