javascript问题?

Question

<input type=text name="fn">
<input type=button onclick="window.open(fn.value,'')" value="打开">

Answer 1

<input type=text name="tt">
<input type=button onclick="window.open(tt.value,"","")" value="open">

Answer 2

<input type=text name="tt">
<input type=button onclick="window.open(tt.value,"100","100"，"100","100")" value="open">

Answer 3

<input type=text name="tt">
<input type=button onclick="window.open(tt.value+'.htm','','')" value="open">