jQuery Grid Plugin - jqGrid

I am new to jqGrid, and having trouble with achieving a couple of tasks. Any guidance will be a huge help.

Issue1# I need to perform following jquery masking on my rate field in the create form,

$('#Rate').priceFormat({ prefix: '', thousandsSeparator: '' }); How could I achieve this in jqGrid?

Issue II: I have a field (CREATE_DATE) whose value needs to be passed in the edit form. To achieve this I have to make it editable, but at the same time I don't want it to display in the edit form. Something similar to this issue (http://stackoverflow.com/quest.....-edit-form)

Issue III: I need to have dynamically populated drop down list.

 $("#HEALTH_PLAN_CATEGORY_VALUE_ID").change(function () {
            $.getJSON('/Ajax/GetCountyForHealthPlan', { id: $(this).val() }, function (counties) {
                var ddlSelectedCounty = $("#COUNTY_GSA_LOOKUP_ID");

                // clear all previous options
                $("#COUNTY_GSA_LOOKUP_ID > option").remove();

                // populate the products
                for (i = 0; i < counties.length; i++) {

                    ddlSelectedCounty.append($("<option />").val(counties[i].Value).text(counties[i].Text));
                }

            });

        });

Issue IV: I will really appreciate if any one can share resources on how to do basic jquery functionality on different jqGrid elements. There wiki is not very helpful to me.

Thanks a lot.