Using calendar information

Would anyone be able to tell me how i go about inputting the selected information from a calendar into a textbox?

I have got the calendar to run my query on the date selected in the calendar and return the info in a datalist....but I want to have a heading saying..Here is the data for the date you selected which was **then the date which was selected here**. I think I may need to use Javascript but unsurre whether there is an easy way to do this or not?

Any help would be gratefully received.

Thanks in advance.
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