2d plot with gnuplot with user defined thickness

hi, i have a set of x,y,t in a text file sect.txt.. first line represents x1,y1,t1 and second is x2,y2,t1... the 4th line(3rd line is blank) is x3,y3,t2, followed by x4,y4,t3... i want to plot line which has coordinates x1,y1 and x2,y2, with thickness = t.. similary next line has coord = x3,y3 and x4,y4 with thickness=t2 and so on for n times.. with the code below, i am able to plot the 2d lines in gnuplot, but unable to incorporate thickness. could anyone suggest.. thanks
0.0000000000000000 5.0000000000000000 5
1084.0000000000000 5.0000000000000000 5

542.00000000000000 10.000000000000000 1
542.00000000000000 981.00000000000000 1

0.0000000000000000 990.50000000000000 2
1084.0000000000000 990.50000000000000 2

392.00000000000000 1017.5000000000000 4.5
692.00000000000000 1017.5000000000000 4.5

392.00000000000000 1682.5000000000000 3
692.00000000000000 1682.5000000000000 3

542.00000000000000 1035.0000000000000 2
542.00000000000000 1665.0000000000000 2

code
set xlabel "X Axis (Major) "
set ylabel"Y Axis (Minor) "
coord="sect.txt"
set timestamp
set autoscale keepfix
set view equal xy
plot coord using 1:2 with linespoints