Form Post monitor

Anyone have any examples of a monitor that uses POST instead of a simple GET? I need to monitor various areas of an http site but I have to authenticate first via form post. It seems the "send string" text box does not accept carriage return/line feed so you can't save something like

 

 

POST /login.aspx?ReturnUrl=%2fDefault.aspx HTTP/1.1

 

Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*

 

Accept-Language: en-us

 

Content-Type: application/x-www-form-urlencoded

 

 

Thanks for any assistance