I'm stuck on this! Need some help.

1. Create a web page in HTML that contains a form with five text boxes labeled:
   • Last score entered.
   • Total of scores
   • Average of scores.
   • Highest score.
   • Lowest score.
2. Add a button to the form in Javascript. When the button is pressed, prompt the user to enter a test score between 0 and 100 =or= to enter 999 in order to end the program.
   • When the user enters 999, the prompt should no longer re-appear
   • If the user enters a non-numerical value, the prompt should re-appear, with an updated message indicating that there was an error in the input
   • If the user enters a value less than zero or more than 100, the prompt should re-appear, with an updated message indicating the error in the input
   • If the user enters a value between zero and 100:
     • update variables to store the most recently entered value, the new total, the new average, a new best score (if applicable) and a new worst score (if applicable)
     • The prompt should re-appear to allow users to enter a new value
   • When the loop is complete, the last entered score, the total of scores, the average score, the best score and the worst score should all display on the page