How do I add a class to an @Html.ActionLink?

The problem is that class is a reserved word in C#. You can specify that you want to use the name 'class' as your attribute name by escaping it with the @ symbol like so:

 @Html.ActionLink("Print PO", "PoReport", new { id = 51970}, new { id = "PoPrint", @class = "PoClass"})

You have to indicate the action name, controller and url parameters (null in this example)

@Html.ActionLink("Link Name", 
"ActionName",
"ControllerName",
null,
new { @class = "your css class" }
)

You have to use the @ character, since class is a keyword in C#. Here's a link to the MSDN documentation: http://msdn.microsoft.com/en-us/library/dd492124(v=vs.108).aspx

@Html.ActionLink("Link Text", "ActionName", 
         new { controller = "MyController", id = 1 }, 
         new { @class = "my-class" })