java-script validation on text box for already existing condition

Question

I want to do this type of validation using javascript on text box in asp.net on textchange event of text box below is my code in c# validtaion:

string str = "Select ReceiptNo from BranchOutwardItems where ReceiptNo='" + txtReceiptNo.Text + "'";

DataTable dt = objGlobalClass.LoadData(str);
if (dt.Rows.Count > 0)
{
     lblMsg.Text = " Receipt ID already exists.Click On ADD for Generate New Receipt ID";
}
else
{
     lblMsg.Text = "Receipt ID doesnot exists";
}

This is not a good idea becuase: 1. javascript validation could be eliminated easily; 2. the code given is a good candidate for SQL injection. — i100
– i100, Commented Oct 29, 2012 at 7:12
You should use focus out. Because you are going to hit the database for each character change. Your will have to create a Web-Service or page method or http-handler which takes the value from java-script and return the appropriate message. — शेखर
– शेखर, Commented Oct 29, 2012 at 7:22

शेखर · Accepted Answer · 2012-10-29 07:29:01Z

1

For this you will have to call a Page-Method or A Web-Service, Or a Http-Handler to validate the value of the text box.

Here is a similar example
Here too is a good example

answered Oct 29, 2012 at 7:29

शेखर

17.6k14 gold badges64 silver badges123 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Pavan Kumar · Accepted Answer · 2012-10-29 07:12:35Z

0

var tbl = document.getElementById('tblID');
var lbl = document.getElementById('lblID');
if(tbl != null)
{

if(tbl.rows.length > 0)
{
lbl.innerHTML = "Success Message";
}
else 
{
lbl.innerHTML = "Failed Message";

}

}

answered Oct 29, 2012 at 7:12

Pavan Kumar

1902 silver badges8 bronze badges

Collectives™ on Stack Overflow

java-script validation on text box for already existing condition

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related