<script>
var titleB = document.getElementbyid('inputvalue');

var regex= /fuck/gi;
titleB.value=titleB.value.replace(regex, "fudge");

</script>

>> var data = "abc d abc gef a";
undefined
>> data
"abc d abc gef a"
>> var regex = /abc|gef/gi;
undefined
>> data.replace(regex,"fudge");
"fudge d fudge fudge a"