First, you are calling document.getElementById(), but your div does not have an ID of terminal, it has a class called terminal.
Second, you are using jQuery but then switch back to classic JavaScript. You could update your code to the following:
success: function (data) {
//alert(data);
// we need to update the elements on the page
var existingHtml = $(".terminal").html();
$(".terminal").html(existingHtml + mydata + data);
}
Note that the $(".SomeName")
selector is for selecting by class and $("#SomeName")
is to select by id.
Edit and Note
If this terminal div could start to get a lot of data inside of it, you may look at using the .append()
function in jQuery to prevent having to make a copy of the HTML and overwrite the HTML each time a request is made. The update would be something similar to the following (its a little shorter and should be more efficient as well)
success: function (data) {
//alert(data);
// we need to update the elements on the pag
$(".terminal").append(mydata + data);
}