Draggable Alert Executor Program

document.body.outerHTML = '<div id="mydiv" style="position: absolute;"><div style="background: blue; width: 500px; height: 25px; top: 11px; left: 9px;"><a style="color:white">⠀⠀⠀⠀⠀Website Alerter v2.11</a>⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀<a onclick="closeAlert()" style="color:red">[X]</a></div><div style="background-color: lightgray;border-color: black;width: 500px;height: 20px";>⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀⠀<button onclick="setAlertMod()">Set Alert Text</button><button onclick="modmenualert()">Execute!</button></div></div>'+document.body.outerHTML;
// Make the DIV element draggable:
dragElement(document.getElementById("mydiv"));

function dragElement(elmnt) {
  var pos1 = 0, pos2 = 0, pos3 = 0, pos4 = 0;
  if (document.getElementById(elmnt.id + "header")) {
    // if present, the header is where you move the DIV from:
    document.getElementById(elmnt.id + "header").onmousedown = dragMouseDown;
  } else {
    // otherwise, move the DIV from anywhere inside the DIV:
    elmnt.onmousedown = dragMouseDown;
  }

  function dragMouseDown(e) {
    e = e || window.event;
    e.preventDefault();
    // get the mouse cursor position at startup:
    pos3 = e.clientX;
    pos4 = e.clientY;
    document.onmouseup = closeDragElement;
    // call a function whenever the cursor moves:
    document.onmousemove = elementDrag;
  }

  function elementDrag(e) {
    e = e || window.event;
    e.preventDefault();
    // calculate the new cursor position:
    pos1 = pos3 - e.clientX;
    pos2 = pos4 - e.clientY;
    pos3 = e.clientX;
    pos4 = e.clientY;
    // set the element's new position:
    elmnt.style.top = (elmnt.offsetTop - pos2) + "px";
    elmnt.style.left = (elmnt.offsetLeft - pos1) + "px";
  }

  function closeDragElement() {
    // stop moving when mouse button is released:
    document.onmouseup = null;
    document.onmousemove = null;
  }
}; function modmenualert() { confirm(alertModPrompt); };
function closeAlert() { document.getElementById("mydiv").outerHTML = ""; };
function setAlertMod() { var glizzyX = prompt("What do you want the alert to say?"); alertModPrompt = glizzyX; };
var alertModPrompt = "error";