I am working on java scripts and xhtml. Here is the requirements for the case problem.Complete the following:1. Using your text editor, open twinstxt.htm, tlmtxt.css, and fonttxt.js from thetutorial.13case1 folder. Enter your name and the date in the head section, and thensave the files as twins.htm, tlm.css, and fontsizer.js, respectively.2. Go to the twins.htm file in your text editor and add a script element linking to thefontsizer.js file.3. Scroll down the file and locate the fontbuttons div element, which contains twoimage buttons. Place both image buttons in the fontsizer class. Set the values associatedwith those buttons to ‑0.1 for the fontdown.png image and 0.1 for fontup.png.4. Save your changes to the file, and then go to the tlm.css file in your text editor.5. At the bottom of the file, insert a style rule to set the width of the inline image withinthe figure box in the article element to 12em.6. Add another rule to set the font size of paragraph text within the article element to1em.7. Save your changes to the file, and then go to the fontsizer.js file in your text editor.8. Add a command to run the startup() function when the page is initially loaded by thebrowser.9. Create the startup() function. The purpose of this function is to apply onclick eventhandlers to the two font resize buttons. Create the fontButtons variable containingall of the page elements that belong to the fontsizer class. Loop through that collectionand add an event handler to each item in the collection to run the resizeText()function when clicked.10. Create the resizeText() function. The purpose of this function is to change the defaultfont size of the document body based on the value of the font button being clicked.When that value is changed, all object sizes based on em units automatically will beresized. Add the following commands to the function:a. Using the parseFloat() function, store the numeric value of the button beingclicked in the fontChange variable.b. Next, you must determine whether an inline style has been used to set the defaultdocument body font size. First, test whether the font size of the document bodyis equal to an empty text string. If it is, set the font size to 1.0em. (Hint: Use thereference document.body to reference the document body.)c. Use the parseFloat() function to store the numeric value of the document bodyfont size in the currentFontSize variable.d. Change the document body font size to the text stringcurrent font size + font change + “em”where current font size is the value of the currentFontSize variable and fontchange is the value of the fontChange variable.11. Document your code with appropriate comments throughout.12. Save your changes to the file, and then load twins.htm in your Web browser. Verifythat when you click the buttons to increase or decrease the font size, the paragraphtext and the size of the author’s photo change in response, but no other part of theWeb page changes in size.I have attached and uploaded the original files as well the files I have been working on. Please add comments to all the additions and work you make to the file as this will help me understand. Thank you for any and all help.