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 ( columnChooser.getItemCount( ) > 0 )
		{
			columnChooser.select( 0 );
		}
		columnChooser.setEnabled( columnChooser.getItemCount( ) > 0 );
		updateMessageLine( );
	}
	private boolean matchDataType( ResultSetColumnHandle column )
	{
		String type = getSelectedDataType( );
		if ( type.equals( DesignChoiceConstants.PARAM_TYPE_STRING )
				|| DesignChoiceConstants.COLUMN_DATA_TYPE_ANY.equals( column.getDataType( ) ) )
		{
			return true;
		}
		if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DATETIME.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_DATETIME );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_DECIMAL.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_DECIMAL );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_FLOAT.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_FLOAT );
		}
		else if ( DesignChoiceConstants.COLUMN_DATA_TYPE_INTEGER.equals( column.getDataType( ) ) )
		{
			return type.equals( DesignChoiceConstants.PARAM_TYPE_FLOAT )