Is there any DIRECT flights from Las Vegas to Seattle and if so what is the flight time ?

Yes, there are direct flights available from Las Vegas to Seattle. Check sidestep.com. You can use many filters to get the best flight(s) for your situation. I’ll check now, and edit my answer in a few minutes if you’d like.

When do you want to travel (i.e., dates and time of day if applicable)? Also, are you only going one way, or would you like a round-trip?

Edit: Here are some one-way nonstop flights (I used Monday, March 23, as the date), sorted by airline and departure time. Note that I included surrounding airports in my search, and I still ended up with these results.

Alaska Airlines has departures from LAS at 7:00am, 9:10am, 11:20am, 1:40pm, 4:48pm, 6:55pm, and 8:45pm. Their flights are operated by Boeing 737-800 and -900 (NG) aircraft, are 2h40m long on average, and cost on average $212 (range is from $161-252).

Southwest Airlines has departures from LAS at 6:25am, 10:50am, 4:00pm, and 9:45pm. Their flights are operated by Boeing 737-700 (NG) aircraft, and are 2h45m long on average. To find prices, you need to check http://www.southwest.com, as SideStep does not show Southwest’s prices.

US Airways has two departures from LAS: one at 11:40am, and the other at 7:25pm. Their flights are operated by Airbus A319 and A320 aircraft, are 2h41m long on average, and cost on average $176.
__________

EDIT 2: What day of the week are you thinking of? The best day to travel from what I am told is Tuesday. I can’t search a whole month right now, but here’s what I got for July 14:

Alaska Airlines has departures from LAS at 7:00am, 9:15am, 11:00am, 2:00pm, 5:55pm, and 8:45pm. Their flights are operated by Boeing 737-800 and -900 (NG) aircraft, are generally 2h33m long, and cost on average $108.

US Airways has two departures from LAS: one at 11:4am, and the other at 7:30pm. Their flights are operated by Airbus A319 and A320 aircraft, are 2h41m long on average, and cost on average $115.

Southwest Airlines has no direct flights on July 14th.

Send me an email if you’d like, and when I get the chance (maybe later today or tomorrow) I’ll try and help you out a bit more.