You use the Create Parameter Field dialog box to describe your parameter.
1. Enter a Name for the parameter. It can have any name, up to 25*1 characters.
2. Next add Prompting Text. This is the message users will see. when being prompted to enter a value for the parameter. This text can be up to four lines of 60-70 characters each, until reaching the 254 character limit.
3. Select the Value Type of the field from the list. If the value entered fr the parameter needs to match against a database field, be sure to scale-the same value type as the database field’s data type.
4. Do you want users to be able to enter multiple values at the prompt? If yes, select the Allow. Multiple Values check box. If you check this box, the Discrete and Range Values option becomes available
5. Select Discrete Value(s) if you want the prompt to accept only single. Values, not ranges Select Range Value(s) if you want the prompt to accept the start and end values of a range. Or, select Discrete and Range Values if you want’ to allow users to enter both kinds of values.
6. Click the Set Default Values button if you want to set a default or specify a pick list of values. This opens the Set Default Values dialog box.
The check box “Allow editing of default values when there is more, than one value” allows users to type their own value at the prompt rather than having to pick a value from the list. Clearing this check box forces user to select a value from the list.