#Define title and matrix size
wm title . "Entry Matrix using grid command"
set rows 4
set columns 4

#Using loop to create entry cells and then packing them using grid command
for {set i 1} {$i <= $rows} {incr i} {
for {set j 1} {$j <= $columns} {incr j} {
set m($i$j) "label$i$j"
entry .e$i$j -width 12 -justify center -textvariable m($i$j)
grid .e$i$j -row [expr $i-1] -column [expr $j-1]
}
}

button .print -text Print -command printout
button .exit -text Exit -command exit
grid .print .exit -columnspan 2

proc printout {} {
global m rows columns

for {set i 1} {$i <= $rows} {incr i} {
for {set j 1} {$j <= $columns} {incr j} {
puts $m($i$j)
}
}
}

#Note: the advantage of grid command is to align elements into row and/or column style.
#(P.Pongcharoen 2/2001).