Using PagedList to add paging function to ASP MVC3 website - asp.net-mvc

Question

One of the search functions to our website returns far too many results for one page to handle, so I am trying to add the paging function as provided by here: https://github.com/TroyGoode/PagedList
The solution builds properly and the page will load as well, however when I try to conduct a search a "NotSupportedException" is thrown on the page's controller/Index() method:
The method 'Skip' is only supported for sorted input in LINQ to Entities. The method 'OrderBy' must be called before the method 'Skip'.
Visual Studio 2010 points to the return statement when this exception is thrown. This is only my second day working in ASP MVC so any and all suggestion are welcome. Thank you!
case "name":
//if no comma, do a combined search by last name and by corporate name.
searchString = searchString.ToUpper();
var lastAgents =
db.Agent.OrderBy(s => s.LastName).Where(s => s.LastName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification).Include(a => a.SymetraNumberToAgentId);
//end new code
var corp2Agents =
db.Agent.OrderBy(s => s.CorporateName).Where(s => s.CorporateName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification);
if ((corp2Agents.Count() == 0) & (lastAgents.Count() == 0)) ViewBag.ErrorMessage = "None found in search for Last Names and Companies beginning with " + search1;
else ViewBag.Message = "Results of Last Name and Company Name search. Found " + (corp2Agents.Count() + lastAgents.Count()).ToString();
pageNumber = (page ?? 1);
return View(lastAgents.Union(corp2Agents).ToPagedList(pageNumber, pageSize));

Answer 1

Took forever but I found the answer. Both these statements
var lastAgents =
db.Agent.OrderBy(s => s.LastName).Where(s => s.LastName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification).Include(a => a.SymetraNumberToAgentId);
//end new code
var corp2Agents =
db.Agent.OrderBy(s => s.CorporateName).Where(s => s.CorporateName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification);
contain an OrderBy, however this is necessary in the Union statement as well. The final "return" statement is as follows:
return View((lastAgents.Union(corp2Agents)).OrderBy(s => s.sNumber).ToPagedList(pageNumber, pageSize));

Answer 2

Try adding the .OrderBy(s => s.sNumber) in the controller like this:
var lastAgents =
db.Agent.Where(s => s.LastName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification).Include(a => a.SymetraNumberToAgentId).OrderBy(s => s.sNumber);
//end new code
var corp2Agents =
db.Agent.Where(s => s.CorporateName.ToUpper().StartsWith(searchString)).Include(
a => a.AgentIdentification).OrderBy(s => s.CorporateName);