diff --git a/htdocs/public/payment/newpayment.php b/htdocs/public/payment/newpayment.php
index 8f3bb23a362..bda79d7d97d 100644
--- a/htdocs/public/payment/newpayment.php
+++ b/htdocs/public/payment/newpayment.php
@@ -869,7 +869,7 @@ if (!$source)
 	print '</td><td class="CTableRow'.($var ? '1' : '2').'">';
 	if (empty($amount) || !is_numeric($amount))
 	{
-		print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
+		print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
 		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.price2num(GETPOST("newamount", "alpha"), 'MT').'">';
 	} else {
 		print '<b>'.price($amount).'</b>';
@@ -915,7 +915,7 @@ if ($source == 'order')
 	if ($action != 'dopayment') // Do not change amount if we just click on first dopayment
 	{
 		$amount = $order->total_ttc;
-		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'int');
+		if (GETPOST("amount", 'alpha')) $amount = GETPOST("amount", 'alpha');
 		$amount = price2num($amount);
 	}
 
@@ -961,7 +961,7 @@ if ($source == 'order')
 	print '</td><td class="CTableRow'.($var ? '1' : '2').'">';
 	if (empty($amount) || !is_numeric($amount))
 	{
-		print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
+		print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
 		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.price2num(GETPOST("newamount", "alpha"), 'MT').'">';
 	} else {
 		print '<b>'.price($amount).'</b>';
@@ -1033,7 +1033,7 @@ if ($source == 'invoice')
 	if ($action != 'dopayment') // Do not change amount if we just click on first dopayment
 	{
 		$amount = price2num($invoice->total_ttc - ($invoice->getSommePaiement() + $invoice->getSumCreditNotesUsed() + $invoice->getSumDepositsUsed()));
-		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'int');
+		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'alpha');
 		$amount = price2num($amount);
 	}
 
@@ -1082,7 +1082,7 @@ if ($source == 'invoice')
 	} elseif (empty($object->paye)) {
 		if (empty($amount) || !is_numeric($amount))
 		{
-			print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
+			print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
 			print '<input class="flat maxwidth75" type="text" name="newamount" value="'.price2num(GETPOST("newamount", "alpha"), 'MT').'">';
 		} else {
 			print '<b>'.price($amount).'</b>';
@@ -1198,7 +1198,7 @@ if ($source == 'contractline')
 			}
 		}
 
-		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'int');
+		if (GETPOST("amount", 'alpha')) $amount = GETPOST("amount", 'alpha');
 		$amount = price2num($amount);
 	}
 
@@ -1286,7 +1286,7 @@ if ($source == 'contractline')
 	print '</td><td class="CTableRow'.($var ? '1' : '2').'">';
 	if (empty($amount) || !is_numeric($amount))
 	{
-		print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
+		print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
 		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.price2num(GETPOST("newamount", "alpha"), 'MT').'">';
 	} else {
 		print '<b>'.price($amount).'</b>';
@@ -1359,8 +1359,8 @@ if ($source == 'membersubscription')
 	if ($action != 'dopayment') // Do not change amount if we just click on first dopayment
 	{
 		$amount = $subscription->total_ttc;
-		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'int');
-		$amount = price2num($amount);
+		if (GETPOST("amount", 'alpha')) $amount = GETPOST("amount", 'alpha');
+		$amount = price2num($amount, 'MT');
 	}
 
 	if (GETPOST('fulltag', 'alpha')) {
@@ -1448,8 +1448,8 @@ if ($source == 'membersubscription')
 	{
 		//$valtoshow=price2num(GETPOST("newamount",'alpha'),'MT');
 		if (!empty($conf->global->MEMBER_MIN_AMOUNT) && $valtoshow) $valtoshow = max($conf->global->MEMBER_MIN_AMOUNT, $valtoshow);
-		print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
-		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.$valtoshow.'">';
+		print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
+		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.$valtoshow.'"'.(empty($conf->global->MEMBER_NEWFORM_EDITAMOUNT)?' disabled':' ').'>';
 	} else {
 		$valtoshow = $amount;
 		if (!empty($conf->global->MEMBER_MIN_AMOUNT) && $valtoshow) $valtoshow = max($conf->global->MEMBER_MIN_AMOUNT, $valtoshow);
@@ -1521,7 +1521,7 @@ if ($source == 'donation')
 	if ($action != 'dopayment') // Do not change amount if we just click on first dopayment
 	{
 		$amount = $subscription->total_ttc;
-		if (GETPOST("amount", 'int')) $amount = GETPOST("amount", 'int');
+		if (GETPOST("amount", 'alpha')) $amount = GETPOST("amount", 'alpha');
 		$amount = price2num($amount);
 	}
 
@@ -1587,7 +1587,7 @@ if ($source == 'donation')
 	{
 		//$valtoshow=price2num(GETPOST("newamount",'alpha'),'MT');
 		if (!empty($conf->global->MEMBER_MIN_AMOUNT) && $valtoshow) $valtoshow = max($conf->global->MEMBER_MIN_AMOUNT, $valtoshow);
-		print '<input type="hidden" name="amount" value="'.GETPOST("amount", 'int').'">';
+		print '<input type="hidden" name="amount" value="'.price2num(GETPOST("amount", 'alpha'), 'MT').'">';
 		print '<input class="flat maxwidth75" type="text" name="newamount" value="'.$valtoshow.'">';
 	} else {
 		$valtoshow = $amount;