Hi all
Since we cant create files at mikrotik only by "file print file=name" and the result will be name.txt 
but i wanna to create file called name.html , i cant neither choose the type neither change the name ...

Because RouterOS scripting never had functionality to work with files.
file print file is just a workaround that you can use to make file, nothing more.

Since you can't serve this html file from the router, there is no real difference. To serve the file, you will have to move it to another machine. So during this process, you might as well rename it. 

Thanx all i solve it using fetch from and to the same routerboard 

Because RouterOS scripting never had functionality to work with files.
file print file is just a workaround that you can use to make file, nothing more.

Yea i read about that .... so i made another workaround to solve the problem

Since you can't serve this html file from the router, there is no real difference. To serve the file, you will have to move it to another machine. So during this process, you might as well rename it. 

I m gonna use it to show the expiring date for the hotspot users so i m gonna use it for the same board 

can you share it ?!