How to get element id of Salesforce Visualforce Components to be used in Javascript?

Created Date: <apex:inputText id=”dah” value=”{!created}” size=”50″
onclick=”javascript:go(‘{!$Component.dah}’)”></apex:inputText>

<script>
function go(field) {
var huh = document.getElementById(field).value;
alert(huh); //returns the string u put inside of input text field
}
</script>