How to filter your jquery autocomplete data while typing
var aCleanData = ['aaa','aab','faa','fff','ffb','fgh','mmm','maa'];

$('#my-input').autocomplete({
    source:aCleanData,
    minLength:2
});

var aCleanData = ['aaa','aab','faa','fff','ffb','fgh','mmm','maa'];
$('#my-input').autocomplete({
    source: aCleanData,
    minLength: 2,
    search: function(oEvent, oUi) {
        // get current input value
        var sValue = $(oEvent.target).val();
        // init new search array
        var aSearch = [];
        // for each element in the main array ...
        $(aCleanData).each(function(iIndex, sElement) {
            // ... if element starts with input value ...
            if (sElement.substr(0, sValue.length) == sValue) {
                // ... add element
                aSearch.push(sElement);
            }
        });
        // change search array
        $(this).autocomplete('option', 'source', aSearch);
    }
});

$.ui.autocomplete.escapeRegex=function(){
    return '[^|s]' + $value.replace(/[-[]{}()*+?.,\^$|#s]/g, "\$&");
};

$.extend( $.ui.autocomplete, {
escapeRegex: function( value ) {
    return value.replace(/[-[]{}()*+?.,\^$|#s]/g, "\$&");
},
filter: function(array, term) {
    var matcher = new RegExp( $.ui.autocomplete.escapeRegex(term), "i" );
    return $.grep( array, function(value) {
        return matcher.test( value.label || value.value || value );
    });
}
});