function GetElemByID(elem_name){
return document.getElementById(elem_name);
}

/*** CHECK LOGIN FORM ***/
function CheckLoginForm(){
    usr_name=GetElemByID("username");
     usr_pass=GetElemByID("password");
    login_form=GetElemByID("login_form");

    if(usr_name.value.length>0 && usr_pass.value.length>0)
        login_form.submit();
    else{

        error_field=GetElemByID("error_msg");
        GetElemByID(usr_name.id+"_error_msg").innerText=usr_name.value.length>0?"":"Username missing";
        GetElemByID(usr_pass.id+"_error_msg").innerText=usr_pass.value.length>0?"":"Password missing";

    }
}

/**** CHECK REGISTER FORM ****/
function CheckRegisterForm(){
     fname=GetElemByID("fname");
     lname=GetElemByID("lname");
     email=GetElemByID("email");
     password=GetElemByID("password");
     usr_name=GetElemByID("username");
     con_password=GetElemByID("con_password");
    register_form=GetElemByID("register_form");

    if(usr_name.value.length>0 && fname.value.length>0 && lname.value.length>0 && email.value.length>0 && password.value.length>0 && con_password.value.length>0)
        register_form.submit();
    else{

        error_field=GetElemByID("error_msg");
        GetElemByID(fname.id+"_error_msg").innerText=fname.value.length>0?"":"First name missing";
        GetElemByID(lname.id+"_error_msg").innerText=lname.value.length>0?"":"Last name missing";
        GetElemByID(email.id+"_error_msg").innerText=email.value.length>0?"":"Email missing";
        GetElemByID(password.id+"_error_msg").innerText=password.value.length>0?"":"Password missing";
        GetElemByID(usr_name.id+"_error_msg").innerText=usr_name.value.length>0?"":"Username missing";
        GetElemByID(con_password.id+"_error_msg").innerText=con_password.value.length>0?"":"Password missing";

    }
}