$(document).ready(function() {
//Tooltips
$(".tip_trigger").hover(function(){
tip = $(this).find('.tip');
tip.show(); //Show tooltip
}, function() {
tip.hide(); //Hide tooltip		  
}).mousemove(function(e) {
var mousex = e.pageX + 20; //Get X coodrinates
var mousey = e.pageY + 20; //Get Y coordinates
var tipWidth = tip.width(); //Find width of tooltip
var tipHeight = tip.height(); //Find height of tooltip

//Distance of element from the right edge of viewport
var tipVisX = $(window).width() - (mousex + tipWidth);
//Distance of element from the bottom of viewport
var tipVisY = $(window).height() - (mousey + tipHeight);

if ( tipVisX < 20 ) { //If tooltip exceeds the X coordinate of viewport
mousex = e.pageX - tipWidth - 20;
} if ( tipVisY < 20 ) { //If tooltip exceeds the Y coordinate of viewport
mousey = e.pageY - tipHeight - 20;
} 
tip.css({  top: mousey, left: mousex });
});
});