diff --git a/ui/scripts/sharedFunctions.js b/ui/scripts/sharedFunctions.js
index 0b154522cf6..594f7cc01ac 100644
--- a/ui/scripts/sharedFunctions.js
+++ b/ui/scripts/sharedFunctions.js
@@ -200,10 +200,10 @@ function isValidJsonString(str) {
 cloudStack.validate = {
   vmHostName: function(args) {	  	
 		// 1 ~ 63 characters long 
-		// ASCII letters 'a' through 'z' (case-insensitive), digits '0' through '9', hyphen ('-') 
+		// ASCII letters 'a' through 'z', 'A' through 'Z', digits '0' through '9', hyphen ('-') 
 		// must start with a letter 
 		// must end with a letter or a digit (must not end with a hyphen)
-		var regexp = /^[a-z]{1}[a-z0-9\-]{0,61}[a-z0-9]{0,1}$/;
+		var regexp = /^[a-zA-Z]{1}[a-zA-Z0-9\-]{0,61}[a-zA-Z0-9]{0,1}$/;
     var b = regexp.test(args); //true or false		
 		if(b == false)
 	    cloudStack.dialog.notice({ message: 'message.validate.instance.name' });