vmware change disk from prelocated to growable

https://www.howtogeek.com/313125/how-to-convert-between-preallocated-and-growable-disks-in-vmware/

How to retrieve form values from HTTPPOST

[HttpPost] 
public ActionResult SubmitAction(FormCollection collection)
{
     // Get Post Params Here
 string var1 = collection["var1"];
}