Q: LCD flat screen
A: Baby wipes may work well for removing the crayon as mentioned above, but it is widely discouraged to use anything other than water or a water & alcohol mix. Since it is crayons, I'd say go with the baby wipes to remove the crayon then follow up with a clean soft lint free cloth (microfiber is great) dampened with warm or cold water, or use a mixture of 50% alcohol with 50% cool water (anything else can damage the surface), and follow up with a clean soft lint free cloth to dry. Do not use paper towels or tissues. Be careful not to apply too much pressure on the surface. I normally use just clean tap water (though if you have hard water (water w/high mineral content) you should use distilled or deionized water) on a soft cloth and dry with soft cloth - works great. Below I've included a couple of good websites that cover this.