How to pass a string message to JavaScript alert from CodeBehind in ASP.Net

JavaScript:

     function Showalert()
      {
        alert('Records inserted Successfully!');
      }

when the if condition is true the alert message which gets displayed is 

Records inserted Successfully! I would like to pass this message from codebehind instead of mentioning it in Showalert function itself. So that i do not have to create Showalert1,Showalert2 ..funtions everytime i have a new message to be displayed. How can i do this?