Your code works fine... Which browser does this get affected in?
Give this a try.
.form_edit {
border: 1px solid rgb(102, 102, 102);
background-color: rgb(238, 238, 238);
-moz-border-radius: 15px;
-webkit-border-radius: 15px;
-khtml-border-radius: 15px;
border-radius: 15px;
}