webView.loadRequest(urlRequest) shows use of unresolved identifier

import UIKit

classViewController:UIViewController {
    @IBOutlet weak var webview:UIWebView!
    @IBOutlet weak var searchBar: UIBarButtonItem!
    @IBOutlet weak var Stop: UIBarButtonItem!
    @IBOutlet weak var Reload: UIBarButtonItem!
    @IBOutlet weak var Back: UIBarButtonItem!

    // Page to open at startup
    let homeUrlString="https://www.google.co.jp/"

    override func viewDidLoad(){
        super.viewDidLoad()
        // open a website
        open(urlString:homeUrlString)
    }

    // Open the specified url in web view
    funcopen(urlString:String){
        let url = URL (string: urlString)
        let urlRequest=URLRequest(url:url!)
        WebView.loadRequest (urlRequest)
    }

    @ IBAction func BackButtonTapped (sender: UIBarButtonItem) {

    }
    @ IBAction func reloadButtonTapped (sender: UIBarButtonItem) {

    }

    @ IBAction func stopButtonTapped (sender: UIBarButtonItem) {

    }
}