Programming Forums > Web Development and Design > HTML / XHTML / CSS

leatheljamie · Mar 16th, 2005, 11:04 AM

ok...

im A TOTAL beginner at this so how do i make it so when someone presses submit button and they havent filled in a form a alert message comes up and does not allow for them to continue.

Dizzutch · Mar 16th, 2005, 11:14 AM

you're gonna need to use JavaScript to make an actual pop-up, you can use PHP to display a message, but you can't do pop-ups with PHP. search google, there's a lot of information, and examples out there.
good luck
Dizz

Pizentios · Mar 16th, 2005, 11:17 AM

You could use javascripts to check the form values.

this is what i use. i got it off of some website somewhere, i can't remember which.

(Toggle Plain Text)

 <script language="JavaScript">
 	function checkrequired(which) 
 	{
 		var pass=true;
 		if (document.images) 
 		{
 			for (i=0;i<which.length;i++) 
 			{
 				var tempobj=which.elements[i];
 				if (tempobj.name.substring(0,8)=="required") 
 				{
 		    		if (((tempobj.type=="text"||tempobj.type=="textarea")&&tempobj.value=='')||(tempobj.type.toString().charAt(0)=="s"&&tempobj.selectedIndex==0)) 
 					{
 						pass=false;
 						break;
 						 }
 					  }
 			}
 		}
 		if (!pass) 
 		{
 			shortFieldName=tempobj.name.substring(8,30).toUpperCase();
 			alert("Please make sure the "+shortFieldName+" field was properly completed.");
 			return false;
 		}
 		else
 		{
 		return true;
 		}
 	}
 	</script>

Then to use it in your form do this:

(Toggle Plain Text)

 <form method="post" action="MyAction" onsubmit="return checkrequired(this);">
<input type="text" name="requiredName">
<input type="submit" value="Continue">
</form>

The important part is that you put required infront of all the fields that you want to be checked. Also you need the onsubmit part so the script gets run when the user submits the form.

leatheljamie · Mar 16th, 2005, 2:18 PM

oh thanks for the code.
its working =)

tempest · Mar 16th, 2005, 2:22 PM

however, know that someone can simply type:

javascript:void(checkrequired = function() {return true;});

To get past that, you need code on the server-side to truly check to make sure that the values have been entered or not. Client-side code is unreliable.

Mar 16th, 2005, 11:04 AM	#1
leatheljamie Newbie Join Date: Oct 2004 Posts: 6 Rep Power: 0	help on a form ok... im A TOTAL beginner at this so how do i make it so when someone presses submit button and they havent filled in a form a alert message comes up and does not allow for them to continue.

Mar 16th, 2005, 11:14 AM	#2
Dizzutch Professional Programmer Join Date: Dec 2004 Location: Worcester, MA Posts: 441 Rep Power: 4	you're gonna need to use JavaScript to make an actual pop-up, you can use PHP to display a message, but you can't do pop-ups with PHP. search google, there's a lot of information, and examples out there. good luck Dizz __________________ naked pictures of you \| PFO F@H stats

Mar 16th, 2005, 11:17 AM	#3
Pizentios Programming Guru Join Date: May 2004 Location: Brandon, Manitoba, Canada Posts: 2,023 Rep Power: 7	You could use javascripts to check the form values. this is what i use. i got it off of some website somewhere, i can't remember which. (Toggle Plain Text) <script language="JavaScript"> function checkrequired(which) { var pass=true; if (document.images) { for (i=0;i<which.length;i++) { var tempobj=which.elements[i]; if (tempobj.name.substring(0,8)=="required") { if (((tempobj.type=="text"\|\|tempobj.type=="textarea")&&tempobj.value=='')\|\|(tempobj.type.toString().charAt(0)=="s"&&tempobj.selectedIndex==0)) { pass=false; break; } } } } if (!pass) { shortFieldName=tempobj.name.substring(8,30).toUpperCase(); alert("Please make sure the "+shortFieldName+" field was properly completed."); return false; } else { return true; } } </script> <script language="JavaScript"> function checkrequired(which) { var pass=true; if (document.images) { for (i=0;i<which.length;i++) { var tempobj=which.elements[i]; if (tempobj.name.substring(0,8)=="required") { if (((tempobj.type=="text"\|\|tempobj.type=="textarea")&&tempobj.value=='')\|\|(tempobj.type.toString().charAt(0)=="s"&&tempobj.selectedIndex==0)) { pass=false; break; } } } } if (!pass) { shortFieldName=tempobj.name.substring(8,30).toUpperCase(); alert("Please make sure the "+shortFieldName+" field was properly completed."); return false; } else { return true; } } </script> Then to use it in your form do this: (Toggle Plain Text) <form method="post" action="MyAction" onsubmit="return checkrequired(this);"> <input type="text" name="requiredName"> <input type="submit" value="Continue"> </form> <form method="post" action="MyAction" onsubmit="return checkrequired(this);"> <input type="text" name="requiredName"> <input type="submit" value="Continue"> </form> The important part is that you put required infront of all the fields that you want to be checked. Also you need the onsubmit part so the script gets run when the user submits the form. __________________ Profanity is the one language that all programmers understand. Check out my Blog <---updated Nov 30 2007!

Mar 16th, 2005, 2:22 PM	#5
tempest Programming Guru Join Date: Oct 2004 Posts: 1,041 Rep Power: 6	however, know that someone can simply type: javascript:void(checkrequired = function() {return true;}); To get past that, you need code on the server-side to truly check to make sure that the values have been entered or not. Client-side code is unreliable. __________________

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Mar 16th, 2005, 2:18 PM	#4
leatheljamie Newbie Join Date: Oct 2004 Posts: 6 Rep Power: 0	oh thanks for the code. its working =)

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Web Development and Design > HTML / XHTML / CSS

help on a form