Remmy112, If constructive criticism that is clear and to the point is considered a "dick comment", you are right.
Kumar Suhel, is it possible for you to upload your capx (using dropbox, for example)?
The answer to your question depends a lot on how you have things set up in your capx at the moment.
There are many examples on the forum and in the tutorial section on things like how to display high score and this site has a great search function.
One possible way is to have a global variable "Score" and a global variable "Highscore" and chek if the variable "score"is higher than the variable "Highscore"
system compare two values - "Score" > "Highscore" - System set variable "Highscore" = "Score"