var k=0;

   var df;

window.onload=function() {

   df=document.forms[0];

df[1].onkeyup=function() {

df[0].value+=df[1].value.charAt(k);

   k++;

for(c=0;c<df[1].value.length;c++) {

   df[1].value=df[1].value.replace(df[1].value.charAt(c),'#');

   }

  }

 }

I have taken this script from
https://jsfiddle.net/MatPreuter/c2044Lk4/

It is masking to * on the event onkeyup and onkeydown, but i wanted it mask as * without revealing what i have typed.