A web page authoring tool is provided enables a developer to interact with run-time output presentation of a page being authored. A retractable plunger aligns with a chassis structure so that insertion of the support posts in the slots compresses the plunger to a retracted position. In aspects, the source data accepted into the modeling client can include consumer or business-level applications, whose spreadsheet, database or other content can be extracted and encapsulated in extensible markup language or other object-oriented format. The voice signal detection portion is configured to detect a communication status, control the self-adaptive filter according to the communication status, and control startup of the path change detection portion according to the communication status. A salt grid is also disclosed which has a series of lips at the peripheral edge with each lip joining with the rest of the salt grid about a linear hinge line. A user may also employ search criteria to filter the map display of spectrum allocation information by a specific frequency range, holderlicensee name, channel block, time window, lease or license expiration data, and other criteria.