"myURL" is not a valid URL. If you have a string variable that holds your URL then drop the quotes when you use it.
Thanks! In my example I put in the quotes accidentally. Thanks for the response.. this problem has been very frustrating to say the least.
In your example you are only specifying the "cURL" parameter. This is allowed as all other parameters are optional, which means cSubmitAs will be the default "FDF" (your data is being submitted as an FDF). If you read the documentation for submitForm, it states that when submitting as FDF or XFDF, your URL must end in #FDF - for example:
var myURL = "http://my.company.com/path/to/servlet.jsp#FDF";
If you do not included #FDF at the end of your URL and try to submit as FDF, you will get a bad argument error as you are getting now. Are you appending #FDF to your URL as the documentation says to?