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
else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL.equals( getSelectedDataType( ) ) )
		{
			return DataTypeUtil.toBigDecimal( value );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( getSelectedDataType( ) ) )
		{
			return DataTypeUtil.toDate( value, ULocale.US );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_FLOAT.equals( getSelectedDataType( ) ) )
		{
			return DataTypeUtil.toDouble( value );
		}
		return value;
	}
	private IChoiceSet getFormatChoiceSet( String type )
	{
		IChoiceSet choiceSet = null;
		if ( DesignChoiceConstants.PARAM_TYPE_STRING.equals( type ) )
		{
			choiceSet = DesignEngine.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_STRING_FORMAT_TYPE );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DATETIME.equals( type ) )
		{
			choiceSet = DesignEngine.getMetaDataDictionary( )
					.getChoiceSet( DesignChoiceConstants.CHOICE_DATETIME_FORMAT_TYPE );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL.equals( type )
				|| DesignChoiceConstants.PARAM_TYPE_FLOAT.equals( type ) )
		{