Why does the checkbox stay checked when reloading

Question

I'm reloading a web page that has the following code:

<label for="showimage">Show Image</label>
<input id="showimage" name="showimage" type="checkbox" value="1" />

Even though the HTML stays sent to the browser is the same for each reload of the page, the checkbox always takes on the checked value when a reload was performed. In other words, if the user checks the checkbox and reloads, the checkbox is still checked.

Is there some caching going on here?

Edit: I tried Gordon Bell's solution below and find that this is still happening even after removing the value="1". Anything else I might be missing?

<label for="showimage">Show Image</label> 
<input id="showimage" name="showimage" type="checkbox" /> 

Answer 1

It could be due to a browser caching - very useful for static web sites that are not changed too often, very bad for dynamic web applications.
Try with those two meta tags in the head section of the page. Second meta tag is for older browsers (IE5) that are not recognizing "no-cache" meta tag and although different produces the same result: Each request goes to the server.

<META HTTP-EQUIV="Pragma" CONTENT="no-cache"> 
<META HTTP-EQUIV="Expires" CONTENT="-1">

Answer 2

It is a nice feature of Firefox: if you type something but reload the page, the text remains in the text area. Idem for other settings you have chosen.

Alas, it doesn't work in SO (probably reset by JS) and dumber browsers like IE...

Which suggest a solution: if you really need to do that, reset the form with JS. form.reset() might do the job (acts like the Reset input button).