[devote]

var str = 'avtor:ivan+kino:dom 2+kniga:100%+';

var arr = str.split("+"),
    part, parts = {};

while( part = arr.shift() ) {

    part = part.split(":");

    if ( part[0] ) {
        parts[ part[ 0 ] ] = part[ 1 ] || "";
    }
}

alert( [ parts.avtor, parts.kino, parts.kniga ] );