I hope the title is clear enough to help people search for this.

I’ve spent the last few days creating an application for myself to keep track of services performed and clients. I was making a simple “client search” form when I found I was getting inconsistent DB results. Sometimes the results would show up, sometimes not. I won’t go into the full story and how ridiculously long it took me to notice that I wasn’t submitting the form the same way every time. Sometimes I clicked the submit button, sometimes I just hit Enter.

I was invoking the search function based on a cfif tag.

Originally I’d coded this:

<cfif isDefined("FORM.Submit")>
     <cfinvoke component="client_tracking.functions.dbactions" method="searchclients" search=#FORM.search#>
</cfif> 

I did a relatively extended Google search since I wasn’t entirely sure how to word the question properly, but eventually I discovered a better way of checking if the form had been submitted.

Namely:

<cfif structKeyExists(form, "search")>
     <cfinvoke component="client_tracking.functions.dbactions" method="searchclients" search=#FORM.search#>
</cfif> 

This new code checks the form structure and the search key to check if it has value. It works both clicking the submit button and hitting the enter key.

Thanks for Ray Camden for having this figured out ages ago.

One of my favorite perks of my job is that I am constantly learning something new. Even the most seasoned computer expert will never be short of new material.

Today, my lesson was that yes, a microwave can bring a wireless network to its knees.

It was hard to believe at first, but after a few tests it was most certainly the microwave to blame. It seemed to me that this should be a cause for concern and that this sort of radiation could be a sign of something perhaps dangerous. Later, I began some research. According to this article, tests indicate a Microwave oven can degrade network performance by up to 85%. In the case I experienced today, it killed it entirely. However, the article also notes that Microwaves operate at a fairly narrow frequency range, which allows us to alter the WIFI frequency channel to compensate. Often, routers do a scan themselves to see which channel is the clearest, but unless the microwave is running while it does this scan, this will not help.

Some cordless phones are known to interfere with the spectrum as well. Wireless b products operate on the same frequency as older cordless phones (2.4 GHz – close to the same frequency as Microwave ovens) and thus can cause heavy interference. Newer “digital band” cordless phones are available in the 6 GHz range to combat this phenomenon.

Wireless N routers – the newest wireless format available and undoubtedly the best – can eliminate this issue by operating in the 5 GHz range instead of the 2.4 GHz, but all devices in the home would have to be Wireless j technology. Unfortunately, the technology is so new (the technology standard was only officially ratified in October of 2009) that most consumer devices are still b or g technology unless manufactured late 2009.

Most modern wireless routers should have an option to change the frequency channel. For information on how to do this, consult your device documentation or a local computer technician.