Update index.html

    <head>
        <meta charset="utf-8" />
        <meta name="format-detection" content="telephone=no" />
        <meta name="viewport" content="user-scalable=no, initial-scale=1, maximum-scale=1, minimum-scale=1, width=device-width, height=device-height, target-densitydpi=device-dpi" />
        <link rel="stylesheet" type="text/css" href="css/index.css" />
        <title>RunforHealth/title>
                   
        <SCRIPT LANGUAGE="JavaScript">
            var ms = 0;
            var state = 0;
            function startstop() {
                if (state == 0) {
                    state = 1;
                    then = new Date();
                    then.setTime(then.getTime() - ms);
                } 
                else {
                    state = 0;
                    now = new Date();
                    ms = now.getTime() - then.getTime();
                    document.stpw.time.value = ms;
                }
            }
            
            function swreset() {
                state = 0;
                ms = 0;
                document.stpw.time.value = ms;
            }
            function display() {
                setTimeout("display();", 50);
                if (state == 1)  {now = new Date();
                ms = now.getTime() - then.getTime();
                document.stpw.time.value = ms;
            }
            }
            </SCRIPT>          
    </head>

<body onLoad="display()">
        
        <FORM NAME="stpw">
        Time:
        <INPUT TYPE="text" Name="time">
        <INPUT TYPE="BUTTON" Name="ssbutton" VALUE="Start/Stop" onClick="startstop()">
        <INPUT TYPE="BUTTON" NAME="reset" VALUE="Reset" onClick="swreset()">
        </FORM>
        
        <script type="text/javascript" src="phonegap.js"></script>
        <script type="text/javascript" src="js/index.js"></script>   
    </body>