prevent webpage zooming in mobile

<meta 
     name='viewport' 
     content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0' 
/>
<meta 
     name='viewport' 
     content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0' 
/>