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    <p><strong>You were very close with your code. Here’s some adjustments that fill in the gaps.</strong></p> <p>[Edited to show a single canvas solution]</p> <p>To avoid drawing “a mound of lines” when the user drags their new line, you <em>must</em> clear the canvas during each mousemove and draw just their latest dragging line. </p> <p>Clearing the canvas will also clear any lines previously drawn by the user, so you must redraw the previous lines with every drag. To do that, you must store enough info about each line to redraw it. </p> <p>For each line you will need the starting and ending points (x1/y1 and x2/y2). You can put these starting and ending points in an object and store the line-objects in an array:</p> <pre><code>// an array to store previous lines var storedLines=[]; // to store a new line storedLines.push( { x1:10, y1:20, x2:50, y2:35 } ); </code></pre> <p>This function redraws all the previously drawn lines</p> <pre><code> function redrawStoredLines(){ ctx.clearRect(0,0,canvas.width,canvas.height); if(storedLines.length==0){ return; } // redraw each stored line for(var i=0;i&lt;storedLines.length;i++){ ctx.beginPath(); ctx.moveTo(storedLines[i].x1,storedLines[i].y1); ctx.lineTo(storedLines[i].x2,storedLines[i].y2); ctx.stroke(); } } </code></pre> <p>Now displaying the user’s dragging line is much easier like this:</p> <pre><code>function handleMouseMove(e){ if(!isDown){ return; } redrawStoredLines(); var mouseX=parseInt(e.clientX-offsetX); var mouseY=parseInt(e.clientY-offsetY); // draw the current line ctx.beginPath(); ctx.moveTo(startX,startY); ctx.lineTo(mouseX,mouseY); ctx.stroke() } </code></pre> <p>Here is code and a Fiddle: <a href="http://jsfiddle.net/m1erickson/NnZ7a/" rel="nofollow">http://jsfiddle.net/m1erickson/NnZ7a/</a></p> <pre><code>&lt;!doctype html&gt; &lt;html&gt; &lt;head&gt; &lt;link rel="stylesheet" type="text/css" media="all" href="css/reset.css" /&gt; &lt;!-- reset css --&gt; &lt;script type="text/javascript" src="http://code.jquery.com/jquery.min.js"&gt;&lt;/script&gt; &lt;style&gt; body{ background-color: ivory; padding:10px; } canvas{border:1px solid red;} &lt;/style&gt; &lt;script&gt; $(function(){ var canvas=document.getElementById("canvas"); var ctx=canvas.getContext("2d"); var canvasOffset=$("#canvas").offset(); var offsetX=canvasOffset.left; var offsetY=canvasOffset.top; var storedLines=[]; var startX=0; var startY=0; var isDown; ctx.strokeStyle="orange"; ctx.lineWidth=3; $("#canvas").mousedown(function(e){handleMouseDown(e);}); $("#canvas").mousemove(function(e){handleMouseMove(e);}); $("#canvas").mouseup(function(e){handleMouseUp(e);}); $("#clear").click(function(){ storedLines.length=0; redrawStoredLines(); }); function handleMouseDown(e){ var mouseX=parseInt(e.clientX-offsetX); var mouseY=parseInt(e.clientY-offsetY); isDown=true; startX=mouseX; startY=mouseY; } function handleMouseMove(e){ if(!isDown){ return; } redrawStoredLines(); var mouseX=parseInt(e.clientX-offsetX); var mouseY=parseInt(e.clientY-offsetY); // draw the current line ctx.beginPath(); ctx.moveTo(startX,startY); ctx.lineTo(mouseX,mouseY); ctx.stroke() } function handleMouseUp(e){ isDown=false; var mouseX=parseInt(e.clientX-offsetX); var mouseY=parseInt(e.clientY-offsetY); storedLines.push({x1:startX, y1:startY, x2:mouseX, y2:mouseY}); redrawStoredLines(); } function redrawStoredLines(){ ctx.clearRect(0,0,canvas.width,canvas.height); if(storedLines.length==0){ return; } // redraw each stored line for(var i=0;i&lt;storedLines.length;i++){ ctx.beginPath(); ctx.moveTo(storedLines[i].x1,storedLines[i].y1); ctx.lineTo(storedLines[i].x2,storedLines[i].y2); ctx.stroke(); } } }); // end $(function(){}); &lt;/script&gt; &lt;/head&gt; &lt;body&gt; &lt;p&gt;Drag to draw lines&lt;/p&gt; &lt;canvas id="canvas" width=300 height=300&gt;&lt;/canvas&gt;&lt;br/&gt; &lt;button id="clear"&gt;Clear Canvas&lt;/button&gt; &lt;/body&gt; &lt;/html&gt; </code></pre>
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    1. POremove a previous stroke (make a temporary line) - Javascript / HTML5
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    1. COAwesome! that looks pretty thorough. I'm gonna have to change a few things b/c it doesn't exactly answer the question I asked but this helps immensly.
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    2. COOkay nevermind, I can't figure out how to change it, Can you change it so that you don't have to hold the button down, you just click for the start point and then click again to set the end point.
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    3. COI've edited my answer to be closer to your original code (sorry if I strayed a bit with my original answer).
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