How to Compute Two TextBox Using Jquery

Abraham Olatubosun

Dear code masters,

I believe you are all in good health.

I need your Assistance once again, my challenge is as follows:

Let say i have a webform in ASP.NET, that have two Textbox's Txt1 and Txt2

Txt1 is for previou tempratureand and it is readonly, when the form load previous data from Database is loaded into Txt1 so the user is expected to input current temprature into Txt2 we want Txt2 to validate Txt1 if it is not a space and if it is greater than or equal to zero. If that happens then

Txt1 = Txt1 + Txt2 else

Txt1 = Txt2.

I use Jqeury as follows:

"text/javascript" src="Scripts/jquery-3.1.1.min.js">
"text/javascript">
$(function () {
$('#<%=Text1.ClientID%>').blur(function sumN1() {
var T = $('#<%=TextBox3.ClientID%>').val()
if (T != "" && T >= 0) {
$('#<%=Txt1.ClientID%>').val(+$('#<%=Txt1.ClientID%>').val() + +$('#<%=Txt2.ClientID%>').val());
} else {
$('#<%=Txt1.ClientID%>').val($('#<%=Txt2.ClientID%>').val());
}
})
})

this code works fine, if Txt1 = 50 from load and the user input 10 in Txt2 the result in Txt1 = 60, but the challange is when the user input the wrong figure 10 instead of 5 and the user change it, it add it up so Txt1 became 65 but what we want is for Txt1 to change to 55.

how can we impliment this with the above Jquery.

Thank you all

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Madhanmohan Devarajan9y ago
Accepted answer
In .aspx page:

within jquery:
var hdnvar = $('#<%=hdnvar.ClientID%>').val();
var Txt1 = $('#<%=Txt1.ClientID%>').val();
var Txt2 = $('#<%=Txt2.ClientID%>').val();

if ( Txt2 |=0 && Txt2 >=0)
{
   Txt1 = hdnvar + Txt2;
   $('#<%=Txt1.ClientID%>').val(Txt1);
}
else{
    $('#<%=Txt1.ClientID%>').val(Txt2);
}

Aspx.cs:
hdnvar.Value = 50;
Abraham Olatubosun9y ago
Many thanks Madhanmohan Devarajan i know how to get the hidden field but the assigning of the value is what i will want you to epansiate on .

thanks
Madhanmohan Devarajan9y ago
In this case you need to have the intial value of Txt1 in hidden field. On the page load you will assign the Txt1 value, same way assign the value to hidden field. During the calculation always take hidden field value + Txt2 and store it in Txt1.

Example:

Hidden field value: hdnvar = 50 and Txt1=50 (on page load)

User types the value in Txt2 = 10 (wrong value),
now the Txt1 = hdnvar + Txt2 = 50 + 10=60.

After doing correction to Txt2 =5, now the Txt1 = hdnvar + Txt2 = 50 + 5 = 55.