How to save ID of selected value of dropdownlist

I am new to webmatrix and I have a dropdown list that selects Areas from a table using this code:

<select>
@foreach(var row in SelectArea){
    <option> @row.Areas</option>
 }
 </Select>

In the table, each area has a unique ID. I want to save the ID of the selected area to insert it together with other information into another table in the DB. How do I do that?