html - Reduce textbox height -

i have input type text in form, want reduce height, have tried many things, seems whatever not work, tried line-height, margin etc. below have.

  .txtboxitem{     height: 1em;     font-size:8px;     }

and here markup

<input class="txtboxitem" type="text" id="txt_emailaddress" />

please note, width works fine, font looks small in textbox, why height of textbox not reducing?

edit: think external file has input property "!", anyway can override in local html file?

its working me using px...

input{height:5px;}

edit: i've used code , working in same jsfiddle... http://jsfiddle.net/mvndh/

Silver