i have data in two text box, then i want to match it with data in text file. after match, i want to take value in column 3.

textbox1= 2.9167 will refer to column 1
textbox2 = 101.7745 will refer to column 2

example data in text file:
column1 column 2 column 3

2.9100 101.7705;60
2.9103 101.7767;40
2.9110 101.7756;20
2.9167 101.7744;60
2.9167 101.7745;60
2.9167 101.7746;50
2.9167 101.7747;80

after match value in text box with value in text file, i need value in column 3(e.g 60, in red color). how to write the code?can anyone help me...

thanks..