help in document

[angel.girl]

code 1 <INPUT type=submit value="Sign In" name=.sin>
code 2 <INPUT type=submit value=Finished name=Submit>

here is 2 code i dont understand why 2 number wont work
1 code i use as like
document.all(".sin").click
its working
2nd i use as same but its wont working any one got idea why its wont work???

code 2

<TD noWrap align=right>&nbsp;<INPUT type=submit value=Finished name=Submit>&nbsp;<INPUT type=submit value=Cancel name=.cancel> 
    </TD></TR></TBODY></TABLE></CENTER></FORM></CENTER>

code 1

class=yreglgsb><INPUT type=submit value="sin" name=.save></P></FORM></FIELDSET>