Since your input
is a .span10
, the button should be a .span2
.
<div class="input-append">
<input class="span10" id="msisdn" size="" type="text" name="msisdn"><button class="btn btn-primary span2" type="submit"><i class="icon-plus icon-white"></i></button>
</div>
But the behavior of the button radically changes. You can fix it with this css :
.input-append .btn {
float: none!important;
margin-left: 0!important;
}
And to be even more precise, the button should be as large as a .span2
plus the fluidGridGutterWidth
. Which is width: 17.02127659%
according to the default values.