jQuery Grid Plugin - jqGrid

I'm trying to figure out if my description is confusing. On a regular form, I have those checkboxes shown in my post which are pulled from a MySQL table. How can I get those to load into the jqGrid form for adding a new records or for editing purposes? 

I'm still hoping someone can chine in on checkboxes but perhaps the multiple select is the best option. Is there a way to add tool tips to the multiple select directing how to select multiple?

Anyway here is what I used. If you have suggestions on how to improve this, let me know. It seems there has to be a better way to get the groups on onload without wrapping the grid in the get statement.

$.get('/async/groups.lasso',{x:1}, function(groups){ 

$("#navgrid").jqGrid({

url:"/async/users.lasso",

datatype: "XML",

hidegrid: false,

colNames:["User ID","First Name","Last Name","Email","Password","Groups","Notes","Admin"],

colModel:[

{name:'id', index:'id', width:55, editable:false, editoptions:{readonly:true,size:10}, hidden:true},

{name:'firstname', index:'firstname', width:100, editable:true, editoptions:{size:25}, editrules:{required:true}},

{name:'lastname', index:'lastname', width:100, editable:true, editoptions:{size:25}, editrules:{required:true}},

{name:'email', index:'email', width:100, editable:true, editoptions:{size:25}, editrules:{email:true, required:true}},

{name:'password', index:'password', width:100, editable:true, editoptions:{size:25}, editrules:{edithidden:true}, hidden:true },

{name:'groups', index:'groups', width:100, editable:true, edittype:"select", editoptions:{multiple:true, size:3, value: groups }, sortable:false},

{name:'notes', index:'notes', width:200, editable:true, edittype:"textarea", editoptions:{rows:"3",cols:"26"}, sortable:false},

{name:'isadmin', index:'isadmin', width:60, editable:true, edittype:"checkbox", editoptions:{value:"Yes:No"}, align:"center" }

],

rowNum:10,

rowList:[10,20,30],

pager: '#pagernav',

sortname: "id",

viewrecords: true,

sortorder: "desc",

caption:"Existing Users",

editurl:"/async/users.lasso",

height:210

});

$("#navgrid").jqGrid('navGrid','#pagernav',

{}, //options

{height:320,reloadAfterSubmit:false}, // edit options

{height:320,reloadAfterSubmit:false}, // add options

{reloadAfterSubmit:false}, // del options

{} // search options

);

},"json");