Trying to drag text on canvas

canvas related variables
var canvas = document.getElementById("canvas-wrapper");
var ctx = canvas.getContext("2d");

// variables used to get mouse position on the canvas
var $canvas = $("#canvas-wrapper");
var canvasOffset = $canvas.offset();
var offsetX = canvasOffset.left;
var offsetY = canvasOffset.top;
var scrollX = $canvas.scrollLeft();
var scrollY = $canvas.scrollTop();

// variables to save last mouse position
// used to see how far the user dragged the mouse
// and then move the text by that distance
var startX;
var startY;

// an array to hold text objects
var texts = [];

// this var will hold the index of the hit-selected text
var selectedText = -1;

// clear the canvas & redraw all texts
function draw() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
for (var i = 0; i < texts.length; i++) {
var text = texts[i];
ctx.fillText(text.text, text.x, text.y);
}
}

// test if x,y is inside the bounding box of texts[textIndex]
function textHittest(x, y, textIndex) {
var text = texts[textIndex];
return (x >= text.x && x <= text.x + text.width && y >= text.y - text.height && y <= text.y);
}

// handle mousedown events
// iterate through texts[] and see if the user
// mousedown'ed on one of them
// If yes, set the selectedText to the index of that text
function handleMouseDown(e) {
e.preventDefault();
startX = parseInt(e.clientX - offsetX);
startY = parseInt(e.clientY - offsetY);
// Put your mousedown stuff here
for (var i = 0; i < texts.length; i++) {
if (textHittest(startX, startY, i)) {
selectedText = i;
}
}
}

// done dragging
function handleMouseUp(e) {
e.preventDefault();
selectedText = -1;
}

// also done dragging
function handleMouseOut(e) {
e.preventDefault();
selectedText = -1;
}

// handle mousemove events
// calc how far the mouse has been dragged since
// the last mousemove event and move the selected text
// by that distance
function handleMouseMove(e) {
if (selectedText < 0) {
return;
}
e.preventDefault();
mouseX = parseInt(e.clientX - offsetX);
mouseY = parseInt(e.clientY - offsetY);

// Put your mousemove stuff here
var dx = mouseX - startX;
var dy = mouseY - startY;
startX = mouseX;
startY = mouseY;

var text = texts[selectedText];
text.x += dx;
text.y += dy;
draw();
}

// listen for mouse events
$("#canvas-wrapper").mousedown(function (e) {
handleMouseDown(e);
});
$("#canvas-wrappers").mousemove(function (e) {
handleMouseMove(e);
});
$("#canvas-wrapper").mouseup(function (e) {
handleMouseUp(e);
});
$("#canvas-wrapper").mouseout(function (e) {
handleMouseOut(e);
});

$("#submit").click(function () {

// calc the y coordinate for this text on the canvas
var y = texts.length * 20 + 20;

// get the text from the input element
var text = {
text: $("#theText").val(),
x: 20,
y: y
};

// calc the size of this text for hit-testing purposes
ctx.font = "16px verdana";
text.width = ctx.measureText(text.text).width;
text.height = 16;

// put this new text in the texts array
texts.push(text);

// redraw everything
draw();

});