function init() {

    var originalValue;

    document.getElementById("searchfield").onfocus = function(event) {
        if (originalValue == undefined) {
            originalValue = this.value;
        }
        if (this.value == originalValue) {
            this.value = "";
        }
    }

    document.getElementById("searchfield").onblur = function(event) {
        if (this.value == "") {
            this.value = originalValue;
        }
    }

}