Regarding previous company experience letter

Hello my name is manoj . i am a software developer .actually i worked for 1.3 years in a company but that company didnot give me exp letter because iddidnot inform them while leaving that company. and i worked for another company they given me exp letter of one year and now i want to move to another company then how i will prove that i have worked for two years because  i dont have exp and offer letter of previous company . please suggest me . what i have to do. i am very tense.