how to multi languege

how to multi languege

    function validateEmail(){
        //testing regular expression
        var a = $("#email").val();
        var filter = /^[a-zA-Z0-9]+[a-zA-Z0-9_.-]+[a-zA-Z0-9_-]+@[a-zA-Z0-9]+[a-zA-Z0-9.-]+[a-zA-Z0-9]+.[a-z]{2,4}$/;
        //if it's valid email
        if(filter.test(a)){
            email.removeClass("error");
            emailInfo.text("Valid E-mail please");
            emailInfo.removeClass("error");
            return true;
        }
        //if it's NOT valid
        else{
            email.addClass("error");
            emailInfo.text("Error");
            emailInfo.addClass("error");
            return false;
        }
    }



example
this a code
            emailInfo.text("Error");

how to displey error message multi languege i try to use php code but not work

            emailInfo.text("<?=$errror;?> ");  
this not works :(