Modify the code of Listing 9 1 to also validate that the phone field of the form is not blank Have the program produce only one alert message, saying which field(s) require attention Canceling Default Behavior function checkform() document getElementById( form1 ) onsubmit function() var allowSubmit true if( document getElementById( user ) value ) alert( Name field cannot be blank ) allowSubmit false if(allowSubmit) alert( Data OK submitting form ) return allowSubmit window onload checkform Name Required field Phone Optional field

Question

Modify the code of Listing 9 1 to also validate that the phone field of the form is not blank  Have the program produce only one alert message, saying which field(s) require attention  Canceling Default Behavior function checkform()   document getElementById( form1 ) onsubmit   function()   var allowSubmit   true  if( document getElementById( user ) value      )   alert(  Name field cannot be blank  )  allowSubmit   false    if(allowSubmit) alert(  Data OK   submitting form  )  return allowSubmit      window onload   checkform  Name   Required field  Phone   Optional field

Accepted Answer

The Answer is in the image, click to view ...

Question

Modify the code of Listing 9.1 to also validate that the phone field of the form is not blank. Have the program produce only one