Answers for "how to make a attribute in javascript"

attribute in javascript

elem.hasAttribute(name) //checks for existence.
elem.getAttribute(name) //gets the value.
elem.setAttribute(name, value) //sets the value.
elem.removeAttribute(name) //removes the attribute.
elem.attributes //collection of all attributes.

set property dom javascrpt

document.getElementsByTagName("H1")[0].setAttribute("class", "democlass");

put new attribute on html tag using javascript

// Here's what you do for the style attribute
span.setAttribute("style", "width:110%;float:center;left-margin:-10px;top-margin:-10;");