plus 1 every one second

[prokhaled]

I want to add 1 to value of Input every one second:

I use this code but it does not work right. What is the error ?

<form name=tt>
<input type=text name=number value=1>
</form>

<SCRIPT language="JavaScript">
function Clock()
{
NO=tt.number.value+1;

tt.number.value=NO
}
ID=setTimeout("Clock()",1000)
</SCRIPT>