Why not just change the content of the modal body?
window.switchContent = function(myFile){
$('.modal-body').load(myFile);
};
In the modal just put a link or a button
click here to load another file
If you just want to switch beetween 2 modals:
window.switchModal = function(){
$('#myModal-1').modal('hide');
setTimeout(function(){ $('#myModal-2').modal(); }, 500);
// the setTimeout avoid all problems with scrollbars
};
In the modal just put a link or a button
click here to switch to the second modal