Changing the type in IE with JavaScript

you can do this. However, doing a replace on the outerhtml essentially re-declares the element, so any attribute not explicitly defined in the tag declaration will be forgotten. That is why the text value is saved to a variable first. Unlike jQuery’s attr and prop, this works in all versions of IE. I used a real IE10, and I used IETester for 5.5 thru 9.

Here is a fiddle, code below:

HTML

<input id="myinput" type="password">
<input value="transform" id="transformButton" type="button">

JS

//attach a click handler to the button to make it transform 
//when clicked, via our transform() function below
document.getElementById('transformButton').addEventListener("click", transform);

//flag of whether or not it is a password field or text field
var isPassword = true;
//this function will toggle the input between being a password or a text input
function transform() {
    //copy the element itself, its html source, and value text to a variable
    var myInput = document.getElementById("myinput");
    var oldHtml = myInput.outerHTML;
    var text = myInput.value;
    if (isPassword)
    {
        //replace "password" with "text" in the html if it is a password field
        var newHtml = oldHtml.replace(/password/g, "text");
    }
    else
    {
        //replace "text" with "password" if it is a text field
        newHtml = oldHtml.replace(/text/g, "password");
    }
    //update the html
    myInput.outerHTML = newHtml;
    //restore the text value
    myInput = document.getElementById("myinput");
    myInput.value = text;
    //toggle the isPassword flag
    isPassword = !isPassword;
}