I want to create a script on user inpit for email field to check if the user entered email id belongs to particular domain

e.g. i only want to accept user having gmail id , i.e anyone other than user with gmail id should get error message

 

if ( imput.email_id ! = "what shall i put here  @gmail.com

{

alert( " Please enter your gmail id")

}

 

 

thank you for your help