gistfile1.css

=horizontal-form(!width)
    width = !width
    input
        float: left
        &[type="text"],&[type="select"]
            width: 70%
        &[type="submit"]
            float: right
    label
        +clearfix
        span
            padding: 1px
            display: block
            float: left
            width: 25%
            

=vertical-form(!width)
    width = !width
    & label, input
        display: block

// usage

form#addlinks
    +horizontal-form(300px)

// html

        <form id="addlinks">
            <fieldset>
                <legend>Add Links</legend>
                <label>
                    <span>Link</span>
                    <input type="text" id="link" />
                </label>
                <label>
                    <span>Name</span>
                    <input type="text" id="name" />
                </label>
                <input type="submit" value="Add Link" id="addlink" />                
            </fieldset>
        </form>