stripping out non-numeric values in a list

hi all,

i'm very new to scripting and have the folllowing issue. I have used a few commands to get a list of numbers, but I need to strip away the non-numeric ones, and then need a total of all values. any ideas?

root@unixserver # cat myfile | awk '{print $8}'| sort -rn
1504
1344
896
704
608
448
416
416
000:05:14
000:05:14

The output changes day by day, so trimming the last 2 entries is not really suitable. What I need is the ability to take out whole entries that are not numbers - then the sum of remaining entries.

Many thanks.

Not sure if I got it, maybe something like this (adding all but the lines with the colons):

$> cat infile
1504
1344
896
704
608
448
416
416
000:05:14
000:05:14
$> awk '!/\:/ {a+=$1} END{print "Result:",a}' infile
Result: 6336

thats awesome thanks! I was struggling to figure out what tool to use.