first unbind click and then bind (jquery)

Looking at your question, you do not seem to bind back the click after you unbind it, so it will not fire. (Assuming you've kept the sequence of your functionality right). You'll have to do it this way:

//Set a function with the action you need to do after you click the train
function  trainClick() {
  alert('train is clicked');
  //do some stuff
}

When you're unbinding, call unbind with the function name:

$('#locations').click(function(){
 $('#train').unbind('click',trainClick);
//do some stuff
}

Then, to bind the click (when #close is clicked), you'd use :

$('.close').click(function(){
  $('#train').bind('click',trainClick);
  //do some stuff
}

NOTE :

A better way would be use on and off, if you are using a version greater than jQuery v1.7 because, well.. then it will not work. In the code above, just replace bind with on and unbind with off.

$('#train').on('click',trainClick);
$('#train').off('click',trainClick);

Hope this helps!

BINDING AND UNBINDING HANDLERS

The Key is Scope.

You must declare and define the function (trainClick(){stuff it does}) outside the event-handler so that the other buttons' functions can see it.

Below is an example.

function trainClick()
{
    alert("train is clicked"); //Notice this function is declared outside event handlers below
}
$('#button1').on("click", trainClick); //this calls the above function

$("#button2").on("click",function(){
    $("#button1").off("click",trainClick); //unbinds button1 from trainClick() function (event handler)
});//End Button 2 click

$("#button3").on("click",function(){
    $("#button1").on("click",trainClick); //binds button1 to trainClick() function (event handler)
});//End Button 2 click