html show password

function myFunction() {
  var x = document.getElementById("*passwordbox-id*");
  if (x.type === "password") {
    x.type = "text";
  } else {
    x.type = "password";
  }
}//Javascript show all password textboxes script by me
var k = document.getElementsByTagName('input')
for(i=0;i<k.length;i++){
    if(k[i].type = "password"){
        k[i].type = "text"
    }
}