Get Mouse coordinates inside a Div or an Image

Javascript Course

The JavaScript script presented in this page can be used to Get Mouse coordinates inside a HTML element, usually a Div or an Image.
When mouse moves over the specified element, the X (horizontal) and Y (vertical) coordinates are displayed into a Div.
When the user clicks on that element, it is executed a function that adds the coordinates into a text field.

Script code

- Click on the code to select it.

<div id="divid" style="width:250px; height:100px; background:#0809fe;"></div>
<br/><br/> Click to add the coordinates in this text field.<br/>
<input type="text" name="regcoords" id="regcoords" />
<div id="coords">Coords</div>

<script type="text/javascript">
/*
 Here add the ID of the HTML elements for which to show the mouse coords
 Within quotes, separated by comma.
 E.g.:   ['imgid', 'divid'];
*/
var elmids = ['divid'];

var x, y = 0;       // variables that will contain the coordinates

// Get X and Y position of the elm (from: vishalsays.wordpress.com)
function getXYpos(elm) {
  x = elm.offsetLeft;        // set x to elm’s offsetLeft
  y = elm.offsetTop;         // set y to elm’s offsetTop

  elm = elm.offsetParent;    // set elm to its offsetParent

  //use while loop to check if elm is null
  // if not then add current elm’s offsetLeft to x
  //offsetTop to y and set elm to its offsetParent
  while(elm != null) {
    x = parseInt(x) + parseInt(elm.offsetLeft);
    y = parseInt(y) + parseInt(elm.offsetTop);
    elm = elm.offsetParent;
  }

  // returns an object with "xp" (Left), "=yp" (Top) position
  return {'xp':x, 'yp':y};
}

// Get X, Y coords, and displays Mouse coordinates
function getCoords(e) {
 // coursesweb.net/
  var xy_pos = getXYpos(this);

  // if IE
  if(navigator.appVersion.indexOf("MSIE") != -1) {
    // in IE scrolling page affects mouse coordinates into an element
    // This gets the page element that will be used to add scrolling value to correct mouse coords
    var standardBody = (document.compatMode == 'CSS1Compat') ? document.documentElement : document.body;

    x = event.clientX + standardBody.scrollLeft;
    y = event.clientY + standardBody.scrollTop;
  }
  else {
    x = e.pageX;
    y = e.pageY;
  }

  x = x - xy_pos['xp'];
  y = y - xy_pos['yp'];

  // displays x and y coords in the #coords element
  document.getElementById('coords').innerHTML = 'X= '+ x+ ' ,Y= ' +y;
}

// register onmousemove, and onclick the each element with ID stored in elmids
for(var i=0; i<elmids.length; i++) {
  if(document.getElementById(elmids[i])) {
    // calls the getCoords() function when mousemove
    document.getElementById(elmids[i]).onmousemove = getCoords;

    // execute a function when click
    document.getElementById(elmids[i]).onclick = function() {
      document.getElementById('regcoords').value = x+ ' , ' +y;
    };
  }
}
</script>

Instructions:
- In the variable elmids add the ID of the HTML elements for which you want to get the coordinates. You can add one or more IDs, within quotes, separated by comma (see the comments in code).
- The script must be added in the HTML document, after those elements (indicated before the </body>).

Demo:

<input type="checkbox" name="a_name" value="value" checked="checked" />

#id {
  background:url("path_to_image.png");
  background-size:contain;
  background-repeat:no-repeat;
}

var rest8_7 = 8 % 7;
alert(rest8_7);

$nr = ceil(3.5);
echo $nr;        // 4