My java error ?

Hello there,

First, I'm going to format the code you typed so it's easier to read, and so that you know what I started with:

var randomnumber = getrandomrumber (10) ; 
var guess ; 
var guesscount = 0 ; 
var correctguess = false; 

function getrandomrumber(Upper) { 
  var num = Math.floor (Math.random () * upper) + 1; 
  return num; 
}

do { 
  guess = prompt ("Guess what I am thinking"); 
  guesscount += 1; 
  if (parseint(guess) === randomnumber) { 
    correctguess = true 
  } 
} while ( ! correctguess )

alert ("You took" + guesscount + "guesses to think of correct number")

Here are the things causing errors:

• On the getrandomrumber function, the parameter is Upper, with a capital U, but it is referred to as 'upper' later - these need to match.
• in your do-while loop, parseint() needs to be parseInt() (capital i)

At this point it should work, though I do have a couple of things to point out:

• It might be worth considering using camel casing for your variable and function names - for example, getRandomNumber() can be easier to read with all the letters mashed together. Ultimately, you can do whatever you want, but using typical convention can make it easier for you to read, and make it easier on any teams you might code with in the future.
• The final output (number of guesses to get correct number) does appear once the errors are fixed, but it's missing some spaces - you can fix this by adding spaces on either side of the variable like this:

alert ("You took " + guessCount + " guesses to think of correct number")
//          here ^        and here ^

Hope this helps!