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Exercises

1.Create three buttons, labeled Shoot movies, Shoot guns, and Shoot basketballs. When the user clicks any button, use the onClick event handler to call a function that will send a message based on which button was pressed.
2.Create a form that contains two text fields to receive the user’s name and address. When the user leaves each text field, use the onBlur event handler to check if the user entered anything in the respective field. If the user didn’t, send an alert telling him or her so, and use the focus() method to return focus back to the text field the user just left.
3.Make a link that changes the background color to light blue when the mouse pointer is rolled over it.
4.Create a form that will contain a textbox. After the user enters text, all the letters will be converted to lowercase as soon as he or she clicks anywhere else in the form. (Use the onChange event handler.)
5.Write a script that will detect what event occurred and the pixel positions of a mouse when it rolls over a hotspot in an image map.
6.Create a text field in a form. When the user clicks on a button, a function will be called to make sure the field is not empty. In a JavaScript program use the document.getElementByIdI() method to get a reference to the button object. Use the onclick event property.
7.Write the HTML part of this script to test capturing and bubbling for your browser. Explain the order of event handling.
    document.onclick = function(){
      alert("Document clicked!");
    };

    function buttonClick(){
      alert("Button clicked!");
    }

    function formClick(){
      alert("Form clicked!");
    }

8.Rewrite Example 13.5 using the scripting method. The onload event handler will be used as a property of the window object. The definition of the now() function will be the value assigned to the event handler; it will be anonymous. The onunload event handler will also be made part of the JavaScript code. After you have tested your program, put the JavaScript program in an external .js file. In the HTML file, use the src attribute of the script tag to include the .js file and run your program. All JavaScript is now separated from the HTML markup.


  

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