Please take another look at the coin. The only dual-dated Kennedy halves were struck during the Bicentennial and were dated 1776-1976 - and in any case, JFK was only 9 years old in 1926 so he definitely wouldn't have been on a coin from the Sesquicentennial.
Next, see whether it has a small "D", "S", or no letter between the bottom of JFK's portrait and the date. If it has a D or no letter, it's a standard circulation half made of copper-nickel, not silver, and is only worth 50¢. If it has an S, it could be either copper-nickel or 40% silver. If it has a copper-colored edge it's copper-nickel; plain or grayish would indicate 40% silver. In that case it might be worth about 1/7 the price of 1 oz of silver at the current going rate (which changes a lot).
A 1969 silver Kennedy half dollar is worth $5 inn perfect condition. The value of the silver is worth $2.87.
The 1969 Kennedy half dollar is only 40% silver with a value about $3.25
About $6 for its silver content
The coin is 40% silver and has a value of about $2.00 only for the silver.
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
A 1969 silver Kennedy half dollar is worth $5 inn perfect condition. The value of the silver is worth $2.87.
A 2002-S silver proof Kennedy has an average retail value of $18.00.
If you check the back you'll find that you have a halfdollar. There has never been a US-issued Kennedy silver dollar.
The 1969 Kennedy half dollar is only 40% silver with a value about $3.25
About $6 for its silver content
The coin is 40% silver and has a value of about $2.00 only for the silver.
If the coin is a 1996-S Silver Proof Kennedy Half dollar, average retail value is $12.00 to $15.00
If the coin is a US Kennedy half dollar dated 1974 it has no silver in it and is face value.
The coin has no silver and is just face value, spend it.
Please, turn the coin over and look at the denomination on the back. It's a HALF dollar, not a dollar. The 1964 Kennedy half is a 90% silver coin, but very common. The value would be only for the silver, about $15.00 as of 9-1-11.
It has no silver and is just 50 cents, spend it.
About $15.00, retail.