/* first position in the string is 0! */
<html>
<body>
<script type="text/javascript">
var str="JavaScript is great!"
var pos=str.indexOf("great")
if (pos>=0){
document.write("great found at position: ")
document.write(pos + "<br>")
}else{
document.write("great not found!")
}
</script>
</body>
</html>