trying to use $.post

trying to use $.post

I am trying to use $.post() to perform ajax functions
the bit i am having difficulty with is the callback function

all of the pieces of documentation i find for it (i have read several) give examples with this syntax.

$.post("demo_test.asp",function(data,status){
    alert("Data: " + data + "\nStatus: " + status);
  });

as you can see the function is defined within the $.post() parameters.
however i dont like writing my functions into the properties of jquery methods like this because i think it looks messy and i want the function to be available to other parts of the script. so I would rather do it like this

$.post("demo_test.asp",dothis(data,status));

function dothis(data,status)
{
      alert("Data: " + data + "\nStatus: " + status);
{

but i cant seam to get the syntax correct to make it work this way

how do i fix this?