Pls correct any mistakes and explain also pls help

Question

<script>
// Insert script:
(function(w, d, s, p, a, c) {
w.sfButton = w.sfButton || function(){};
c = d.getElementsByTagName(s)[0];
a = d.createElement(s);
a.async=1;
a.src=p;
c.parentNode.insertBefore(a, c);
})(window, document, 'script', '//www.google.com');

// Text:
sfButton.text = 'Download';

// Styles:
sfButton.styles = {
color: 'rgba(0,0,0,0.7)',
textShadow: '1px 1px 1px rgba(255,255,255,0.4)',
fontFamily: 'Arial,Helvetica,sans-serif',
fontSize: '12px',
borderRadius: '4px',
backgroundColor: '#bb00c2',
'background-image': '-webkit-linear-gradient(#c100d6, #ae00a9)',
'background-image': '-moz-linear-gradient(#c100d6, #ae00a9)',
'background-image': 'linear-gradient(#c100d6, #ae00a9)',
border: 'none'
};
</script>

Answer 1

Kindly share your code here.