How to access data in partialview loaded using Ajax - asp.net-mvc-4

Question

I'm currently building a website where I have to update two separate targets from a single Ajax.BeginForm. I got it working by using an additional container to container the two separate targets. As in:
Original Form
#model Mod1
#using (Ajax.BeginForm("LoadData", new AjaxOptions{UpdateTargetID = "Div1"}))
{
<select id="sel1" name="sel1" onchange="$(this.form).submit">
// ...
</select>
}
#using (Ajax.BeginForm("ProcessData", new AjaxOptions{UpdateTargetID = "Div2"}))
{
<div id="Div1"></div>
// ...
<input type="submit" value="GO!" />
}
Code File
public ActionResult LoadData(int sel1)
{
// loading data from database
return PartialView(mod1);
}
Partial View
#model Mod2
<select id="sel2" name="sel2">
#foreach (var item in Model.SelectItems)
{
<option value="#item.Value">#item.Text</option>
}
</select>
#foreach (var item in Model.CheckBoxItems)
{
<label>#item.Text<input type="checkbox" id="chk1" name="chk1" value="#item.Value"></label>
}
For the processing method, I have tried:
public ProcessData(Mod1 mod1, string[] chk1, int sel2)
However I am unable to retrieve the values for either chk1 or sel2 upon form submission. examination of chk1 and sel2 in Debug mode, chk1 is null while sel2 is 0 (no such value in the select options). Can anyone please offer some insight into the reason for this and also how I can go about solving it. Thank you in advance.

Answer 1

If I understand you correctly you can do what you want y having two submit buttons on the same form, each calling a separate action method. That way each submit button will have access to all the fields in the form. For a detailed explanation of how you can do that see my answer here:
How to use ajax link instead of submit button for form?
Edit
In response to comment: the action method LoadData should return a partial view that contains the other two controls and have the whole begin form included in it:
#using (Ajax.BeginForm("LoadData", new AjaxOptions{
UpdateTargetID = "Div1",
InsertionMode = InsertionMode.Replace
}))
{
<select id="sel1" name="sel1" onchange="$(this.form).submit">
// ...
</select>
}
<div id="Div1">
</div>
<div id="Div2">
</div>
Move this to another partial view:
#using (Ajax.BeginForm("ProcessData", new AjaxOptions{UpdateTargetID = "Div2"}))
{
// ...
<input type="submit" value="GO!" />
}