Calling and binding a C# function to a button in Razor pages, Umbraco

Question

I want to bind this already existing function to a button. The function is tested and it completely working. It is important to me to keep all of the code in one razor page.

@functions
{
    public void LogCheck()
    {
        string loginemail = Request["loginemail"];
        string loginpassword = Request["loginpassword"];
        string requestedUrl = "/randomtestpage1/";

        IMember memberIfApproved = SC.Code.Controllers.UserController.GetByEmail(loginemail);

        if (Membership.ValidateUser(loginemail, loginpassword))
        {
            FormsAuthentication.SetAuthCookie(loginemail, true);
            Response.Redirect(requestedUrl);
        }
    }    
}

<form id="loginForm">
  <div class="form-group">
    <div class="form-group">
      <label class="sr-only form-control-label">Email</label>
      <div class="mx-auto col-sm-10">
        <input class="form-control" name="loginemail" type="email"/>
      </div>
    </div>

    <div class="form-group">
      <label class="sr-only form-control-label">Password</label>
      <div class="mx-auto col-sm-10">
        <input class="form-control" name="loginpassword" type="password"/>
      </div>
    </div>
  </div>

  <div class="form-group">
    <div class="mx-auto col-sm-10 pb-1 pt-1">
      <button id="loginbtn" type="button" class="btn btn-outline-secondary btn-lg btn-block" >@Umbraco.AssignedContentItem.GetPropertyValue("signInButtonText")</button>
    </div>
  </div>
</form>

I tried adding onclick="@LogCheck()" to the button element, but that messes up the syntax.

Compiler Error Message: CS1502: The best overloaded method match for 'System.Tuple.Create(object, int)' has some invalid arguments

I also tried to call it from a jQuery, but again error.

$('#loginbtn').click(function() {
    @LogCheck();
}); 

I tried everything mentioned here.