how to strip rows from a text file?

Can an expert kindly write an efficient Linux ksh script that will strip rows with no numbers from a text file?
Supposing there are three rows that text file called text.txt :

"field1","field2","field3",11,22,33,44
"field1","field2","field3",1,2,3,4
"field1","field2","field3",,,,

The above rows are delimited by commas.

I want to strip out the last row that does not have numbers in the last 4 fields. So the new file text2.txt will only have two rows.
"field1","field2","field3",11,22,33,44
"field1","field2","field3",1,2,3,4

Thanks in advance.

(I suppose an awk command will do the job, but am not sure how to write it. here is a start:
awk '{ if (index($0,"\"\",")==4) {print > "text2.txt" } }' bigfile
:confused:

grep -v ',,' bigfile

Thanks!! Now last question:
How can I integrate this grep with the following awk statement which breaks my bigfile into 2 smaller files?

Here again are the two ksh commands:

grep -v ',,,,' bigfile

awk '{ if (index($0,"\"TG\",")==1) {print > "TG.txt" } else {print > "NoTG.txt"} }' bigfile

Somehow in my awk command above, I want to strip out rows that have the pattern ',,,,' before I print it out to TG.txt or to NoTG.txt. How can I achieve that?
Thanks in advance to all you shell geniuses out there!!

break your code up...makes your code easier to read.could be something like this if i get you right

awk '!/,,,,$/{ if (index($0,"\"TG\",")==1) 
                     {print > "TG.txt" 
                  } 
                else {
                       print > "NoTG.txt"
                } 
               }' bigfile 

I lied when I said that was my last question. :o
Sorry to bother you gentlemen again... can we improve on grep ',,,,' bigfile?

You see, grep ',,,,' bigfile will strip out the first row in this table:
,,,,,22,33,44
"field1","field2","field3",1,2,3,4
"field1","field2","field3",,,,

which is not what I am after. I only want to strip out the rows with ',,,,' at the end of the row. So I only want to search for pattern ',,,,' in the last four chars of the row. Is there a way to grep only the last four characters?

I owe you all a favor!!
:b:

I believe ghostdog74's solution will do what you want. Care to try it out?