1. Write JavaScript program that will promp for a string and then compute and display the number of vowels in that string. You need to use switch stament in your program. 2. Write JavaScript program that will display every other integer counting down from 20 to 0 (inclusive) one per line. 3. Write JavaScript program that will ask user for two strings and check if the second string is the substring of the first string. Display appropriate message. Remember, you may use only the techniques that we covered in class so far, or are in the textbook in the part that we covered. You may embed all three scripts in one html file.