The label has to show the result of sum up cents and bills (LineEdits).
i.e: 
if you introduce 2 in $20 and 5 in $1, vuelto (change) has to show the result of that operation (in this case $45) and change if the amount of any of the cents and bills is changed. I tried to make it but doesn't work:
var bill_box
var billNum
var cent_box
var centNum
var totalNum
var cent_box2
var cent_box3
var cent_box4
var cent_box6
var cent_box7
var cent_box8
var centNum2
var centNum3
var centNum4
var centNum6
var centNum7
var centNum8
var cent1 = 12 #Limit of money
var cent2 = 10
var cent3 = 10
var cent4 = 10
var cent5 = 10
var cent6 = 10
var cent7 = 10
var cent8 = 10
func _process(delta):
bill_box = get_node("bill_box")
billNum = int(bill_box.text)
cent1 = cent1 - billNum
if cent1 < 0:
billNum = 0
cent_box = get_node("cent_box")
centNum = int(cent_box.text)
cent2 = cent2 - centNum
if cent2 < 0:
centNum = 0
cent_box2 = get_node("LineEdit3")
centNum2 = int(cent_box2.text)
cent3 = cent3 - centNum2
if cent3 < 0:
centNum2 = 0
cent_box3 = get_node("LineEdit4")
centNum3 = int(cent_box3.text)
cent4 = cent4 - centNum3
if cent4 < 0:
centNum3 = 0
cent_box4 = get_node("LineEdit5")
centNum4 = int(cent_box4.text)
cent5 = cent5 - centNum4
if cent5 < 0:
centNum4 = 0
cent_box6 = get_node("LineEdit6")
centNum6 = int(cent_box6.text)
cent6 = cent6 - centNum6
if cent6 < 0:
centNum6 = 0
cent_box7 = get_node("LineEdit7")
centNum7 = int(cent_box7.text)
cent7 = cent7 - centNum7
if cent7 < 0:
centNum7 = 0
cent_box8 = get_node("LineEdit8")
centNum8 = int(cent_box8.text)
cent8 = cent8 - centNum8
if cent8 < 0:
centNum8 = 0
totalNum = billNum * 0.25 + 0.50 * centNum + centNum2 * 1 + 2 * centNum3 + centNum4 * 5 + 10 * centNum6 + centNum7 * 20 + 50 * centNum8
$Label20.set_text("Vuelto: $"+str(totalNum))
The code displays the result but only miliseconds and once per LineEdit.
Edit: Problem solved.
