In your previous posts, you've said you are new to Access and asked for detailed instructions so I am going to assume that you haven't created your form yet.
1. Choose "Create form in design view"
2. Click on the text box tool and add a text box to your form.
3. Right-click on the text box (the box that's labeled "unbound"

and choose properties.
4. You are going to set 2 properties. Go to the "All" tab and under "Name" enter StartDate. Under "Format" select the appropriate date format.
5. Now change your text box label. Leaving the Properties window open, go back to your form and this time click on the label box. Go back to the Properties window and change the "Caption" property to Start Date or whatever you want it to say.
6. Create another text box for your end date following the same procedure.
7. Now add a button that will eventually open the report.
Make sure the wizard is on (that's the tool with the magic wand)
8. Click on the button tool and add a button to your form. The wizard will come up with a list of categories and actions. Choose "Report Operations" from the categories list. Choose either "Preview" or "Print" from the list of actions and then hit "Next". You should see your report on the list. Select it and hit "Next". Choose either text or a picture for your button and hit "Finish"
9. Save your form. Call it FORMDATE as Eradic8or suggested.
10. Now you need to modify your query. In the criteria section you probably have something like
between [enter startdate] and [enter enddate]
change this to
between forms!formdate!startdate and forms!formdate!enddate
11. Save the query. Now instead of prompting the user for the dates the query will pull the dates from your form, provided it's open.
12. Open your date form and try it out.
Follow Eradic8or's instructions to add the dates you've entered in your form to the heading of your report.