How do you define a method for text box validation?

Question

Validation ----> Lock the text box without enabling to enter a single letter or a digit or a space or anything.

I just want to know that how do you do hard coding for validation of a text box. If it's a method or seperate function that would be easy for me. Then, it's easy for me to reuse that coding in the key press event of each text box.

Dinusha Gamage · Answer

Dear Friend Thank you very much for your reply. But I need a small clarification about this coding. That is I jz want to know whether Javascript coding can be used in C # coding. Here I'm developing a windows application so... Can you apply these coding to validate text boxes in widows form? Thanks in advance !

Niradhip Chakraborty · Answer

You should call a javascript function in onclick or onkeypress event. I will give you javascript function for the validation. //To check whether a adress is proper email address or not. function isEmail(s){ if (s.search(/^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$/) == -1){ return false; } else{ return true; } } //To check input is dizit or Character. This function will only allow user to enter number function ValidatePhoneNo(Obj){ if(((window.event.keyCode >= 48) && (window.event.keyCode var Value = Obj.value; var len = Value.length; if (len == 3 || len == 7 ){ Obj.value = Value + '-'; return true; } } else{ alert(Phone No Cannot be a Character); return false; } } //the following function will disable a textbox call it in onload.My textbox id is txtVendorName Function disable() { document.getElementById(txtVendorName).disable = true; }

Dinusha Gamage · Answer

Yes. At client side.

Niradhip Chakraborty · Answer

Do you want the validation on client side or server side???