Polyfill for placeholder atttribute in input elements

form.css

input.placeholder {
    color: #999;
}

placeholder-polyfill.js

/* Placeholder fallback for IE */

function isPlaceholderSupported() {
    if( jQuery.support.placeholder !== undefined ) {
        return jQuery.support.placeholder;
    }
    var test;
    jQuery.support.placeholder = false;
    test = document.createElement( 'input' );
    if( 'placeholder' in test ) { jQuery.support.placeholder = true; }
    return jQuery.support.placeholder;
}

if ( ! isPlaceholderSupported() ) {
    $( 'input[placeholder]' ).focus( function() {
        var $this = $( this );
        if ( $this.val() === $this.attr( 'placeholder' )) {
            $this.val( '' ).removeClass( 'placeholder' );
        }
    } ).blur( function() {
        var $this = $( this );
        if ( $this.val() === '' || $this.val() === $this.attr( 'placeholder' )) {
            $this.val( $this.attr( 'placeholder' ) ).addClass( 'placeholder' );
        }
    } ).blur()
        .closest( 'form' ).on( 'submit', function() {
            var $inp = $( this ).find( 'input.placeholder' );
            $inp.each( function( i, $elem ) {
                $elem = $( $elem );
                if( $elem.val() === $elem.attr( 'placeholder' )) {
                    $elem.val( '' ).removeClass( 'placeholder' );
                }
            } );
        } );
}