<!DOCTYPE html>
<html>
<head>
</head>
<body>
<form id="form_id">
<button id="button-id" type="submit">Hello</button>
</form>
<script>
function changeButtonText(text)
{
document.getElementById("button-id").innerHTML = text;
}
/*
run:
the value of the "button-id" will change to 'Click Here'
*/
</script>
<button onclick="changeButtonText('Click Here')">Click To Change The Value</button>
</body>
</html>