"for in" loop producing FF error

[iceman2g]

Can anyone shed some light on why this is producing an error in FF.

<input type="button" name="my_btn" value="Click Here" onclick="for(var j in this) { alert(j + ' : ' + this[j]); }" />

Here's the error

Error: uncaught exception: [Exception... "Component returned failure code: 0x80004005 (NS_ERROR_FAILURE) [nsIDOMNSHTMLInputElement.selectionStart]" nsresult: "0x80004005 (NS_ERROR_FAILURE)" location: "JS frame :: http://localhost/error.html :: onclick :: line 1" data: no]

[gRoberts]

shouldn't it be, foreach(j in this)

[iceman2g]

I'm not sure but is foreach a javascript function?

[gRoberts]

Sorry I completely misunderstood the question. It seems that your trying to read a property that cannot be read basically. Using try{} catch(e){} you can stop errors from appearing.

Also, why are you doing this?