jQuery Grid Plugin - jqGrid

i'm using jqgrid for the first time and all will work fine, but there are two questions, i found no answer.

I'm using 'Form Editing' and my history-field need an empty value, to give the user a blank field to add a new line to the history.

I try it to clear the value whith dataInit, but it is only a init-function. When i close the modal form and get the next data record, or use the next/last button, the history-value will filled again.

2. problem: in my empty fields, the edit form shows me in the textfields an ' ' blank. I hope , i can also use the clear-function from my first question.

3. question:   I need in my delete-form also the history-field but i found no way to integrate it. For an delete-action, user should be add an reason in history.

Hope for some support here. thanks.

cooper64