Discuss "textbox validation" in the JavaScript Programming forum.

todd2006 · #1 (**permalink**) July 2nd, 2008, 11:02 AM

hi,

I have a textbox and i want to see the user has a value entered in it

If he doesnt enter a number value then fire a alert

so right now I am checking that he doesnt press the space bar and have a empty space

here is my code.

But its not working

Code:

if(trim(document.frm1.txtnumber.value)
			{
				alert("enter a value");	
			}


function Trim(s) 
   {
   	// Remove leading spaces and carriage returns
   	while ((s.substring(0,1) == ' ') || (s.substring(0,1) == '\n') || (s.substring(0,1) == '\r'))
   	 { s = s.substring(1,s.length); }
     
   	// Remove trailing spaces and carriage returns
 while ((s.substring(s.length-1,s.length) == ' ') || (s.substring(s.length-1,s.length) == '\n') || (s.substring(s.length-1,s.length) == '\r'))
   	 { s = s.substring(0,s.length-1); }
     
   	return s;
   }

Rebelle · #2 (**permalink**) July 2nd, 2008, 11:13 AM

try this:

Code:

function isNumeric(elem, helperMsg){
	var numericExpression = /^[0-9]+$/;
	if(elem.value.match(numericExpression)){
		return true;
	}else{
		alert(helperMsg);
		elem.focus();
		return false;
	}
}

richyrich · #3 (**permalink**) July 2nd, 2008, 11:23 AM

Try this:-

Code:

function check_no(the_id){
var patt1 = New RegExp("^[0-9]{1,9}$");
 
var the_value = document.getElementById(the_id).value;
 
alert(patt1.test(the_value));
}

This will only allow digits to be in the textbox up to a maximum of 9 digits. Obviously you can change {1,9} to whatever you want the maximum to be.

To call it have something like:-

Code:

<input id="no_only" type="text" size="20" />
<input id="button1" value="Click" type="button" onclick="check_no('no_only');" />

Hope that helps.

todd2006 · #4 (**permalink**) July 2nd, 2008, 12:49 PM

hi,

that works out

Can you guys tell me whats wrong with this code

I have a textbox if he value is blank or no value or if its $0 then i want to fire the alert

I have this code

Code:

var getfinallingtotal=document.frm1.total.value;
		
		If(getfinallingtotal=="" || getfinallingtotal=="$0")
		{
					 alert("enter something");
		}

but it doesnt work any
idea

richyrich · #5 (**permalink**) July 2nd, 2008, 12:54 PM

Try using document.getElementById instead, assuming you have given the textbox an id of total. Also try changing the double quotes to single.

Code:

 
var getfinallingtotal=document.getElementById('total').value;
 
        If(getfinallingtotal==''||getfinallingtotal=='$0')
        {
                     alert('enter something');
        }

todd2006 · #6 (**permalink**) July 2nd, 2008, 01:15 PM

i tried it doesnt work

richyrich · #7 (**permalink**) July 2nd, 2008, 01:30 PM

Quote:

Originally Posted by todd2006

i tried it doesnt work

What do you mean "it doesn't work"?

Do you get any errors? What happens?

I just tried this:-

Code:

function check_box(){
var getfinallingtotal = document.getElementById('total').value;
 
if(getfinallingtotal==''||getfinallingtotal=='$0')
{
alert('enter something');
}
}
 
 
<input id="total" type="text" size="10" />
<input id="button1" type="button" value="Check" onclick="check_box();" />

And it worked fine for me.

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Discuss "textbox validation" in the JavaScript Programming forum.

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