JS Save/Obfusicate Input Per Session

<script>
var i=0;
var p1=window.sessionStorage.getItem('keyval');
alert(p1);
var p=prompt('Enter String');
var coundRnd=0;
for(i=0;i<p.length;i++){
if(i!=p.length){
var N=Math.floor(Math.random()*999999999999999);
document.writeln(p.charAt(i)+":"+N);
window.sessionStorage.setItem('keyval',p.charAt(i)+":"+N);
}
}
</script>

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